{"id":1381,"date":"2024-06-02T22:29:30","date_gmt":"2024-06-02T22:29:30","guid":{"rendered":""},"modified":"2024-06-05T03:10:11","modified_gmt":"2024-06-04T19:10:11","slug":"javascript%e4%b8%93%e9%a2%98%e4%b9%8b%e6%95%b0%e7%bb%84%e5%8e%bb%e9%87%8d","status":"publish","type":"post","link":"https:\/\/www.lccc.top\/?p=1381","title":{"rendered":"JavaScript\u4e13\u9898\u4e4b\u6570\u7ec4\u53bb\u91cd"},"content":{"rendered":"<td class=\"d-block comment-body markdown-body  js-comment-body\">\n<h2 dir=\"auto\">\u524d\u8a00<\/h2>\n<p dir=\"auto\">\u6570\u7ec4\u53bb\u91cd\u65b9\u6cd5\u8001\u751f\u5e38\u8c08\uff0c\u65e2\u7136\u662f\u5e38\u8c08\uff0c\u6211\u4e5f\u6765\u8c08\u8c08\u3002<\/p>\n<h2 dir=\"auto\">\u53cc\u5c42\u5faa\u73af<\/h2>\n<p dir=\"auto\">\u4e5f\u8bb8\u6211\u4eec\u9996\u5148\u60f3\u5230\u7684\u662f\u4f7f\u7528 indexOf \u6765\u5faa\u73af\u5224\u65ad\u4e00\u904d\uff0c\u4f46\u5728\u8fd9\u4e2a\u65b9\u6cd5\u4e4b\u524d\uff0c\u8ba9\u6211\u4eec\u5148\u770b\u770b\u6700\u539f\u59cb\u7684\u65b9\u6cd5\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\" data-snippet-clipboard-copy-content=\"var array = [1, 1, '1', '1'];\n\nfunction unique(array) {\n    \/\/ res\u7528\u6765\u5b58\u50a8\u7ed3\u679c\n    var res = [];\n    for (var i = 0, arrayLen = array.length; i &lt; arrayLen; i++) {\n        for (var j = 0, resLen = res.length; j &lt; resLen; j++ ) {\n            if (array[i] === res[j]) {\n                break;\n            }\n        }\n        \/\/ \u5982\u679carray[i]\u662f\u552f\u4e00\u7684\uff0c\u90a3\u4e48\u6267\u884c\u5b8c\u5faa\u73af\uff0cj\u7b49\u4e8eresLen\n        if (j === resLen) {\n            res.push(array[i])\n        }\n    }\n    return res;\n}\n\nconsole.log(unique(array)); \/\/ [1, &quot;1&quot;]\"><\/p>\n<pre class=\"notranslate\"><span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">array<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-kos\">[<\/span><span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-s\">'1'<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-s\">'1'<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span>\n\n<span class=\"pl-k\">function<\/span> <span class=\"pl-en\">unique<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">array<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span>\n    <span class=\"pl-c\">\/\/ res\u7528\u6765\u5b58\u50a8\u7ed3\u679c<\/span>\n    <span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">res<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span>\n    <span class=\"pl-k\">for<\/span> <span class=\"pl-kos\">(<\/span><span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">i<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-c1\">0<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-s1\">arrayLen<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-s1\">array<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">length<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-s1\">i<\/span> <span class=\"pl-c1\">&lt;<\/span> <span class=\"pl-s1\">arrayLen<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-s1\">i<\/span><span class=\"pl-c1\">++<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span>\n        <span class=\"pl-k\">for<\/span> <span class=\"pl-kos\">(<\/span><span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">j<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-c1\">0<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-s1\">resLen<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-s1\">res<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">length<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-s1\">j<\/span> <span class=\"pl-c1\">&lt;<\/span> <span class=\"pl-s1\">resLen<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-s1\">j<\/span><span class=\"pl-c1\">++<\/span> <span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span>\n            <span class=\"pl-k\">if<\/span> <span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">array<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-s1\">i<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c1\">===<\/span> <span class=\"pl-s1\">res<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-s1\">j<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span>\n                <span class=\"pl-k\">break<\/span><span class=\"pl-kos\">;<\/span>\n            <span class=\"pl-kos\">}<\/span>\n        <span class=\"pl-kos\">}<\/span>\n        <span class=\"pl-c\">\/\/ \u5982\u679carray[i]\u662f\u552f\u4e00\u7684\uff0c\u90a3\u4e48\u6267\u884c\u5b8c\u5faa\u73af\uff0cj\u7b49\u4e8eresLen<\/span>\n        <span class=\"pl-k\">if<\/span> <span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">j<\/span> <span class=\"pl-c1\">===<\/span> <span class=\"pl-s1\">resLen<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span>\n            <span class=\"pl-s1\">res<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">push<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">array<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-s1\">i<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">)<\/span>\n        <span class=\"pl-kos\">}<\/span>\n    <span class=\"pl-kos\">}<\/span>\n    <span class=\"pl-k\">return<\/span> <span class=\"pl-s1\">res<\/span><span class=\"pl-kos\">;<\/span>\n<span class=\"pl-kos\">}<\/span>\n\n<span class=\"pl-smi\">console<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">log<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-en\">unique<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">array<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ [1, \"1\"]<\/span><\/pre>\n<\/div>\n<p dir=\"auto\">\u5728\u8fd9\u4e2a\u65b9\u6cd5\u4e2d\uff0c\u6211\u4eec\u4f7f\u7528\u5faa\u73af\u5d4c\u5957\uff0c\u6700\u5916\u5c42\u5faa\u73af array\uff0c\u91cc\u9762\u5faa\u73af res\uff0c\u5982\u679c array[i] \u7684\u503c\u8ddf res[j] \u7684\u503c\u76f8\u7b49\uff0c\u5c31\u8df3\u51fa\u5faa\u73af\uff0c\u5982\u679c\u90fd\u4e0d\u7b49\u4e8e\uff0c\u8bf4\u660e\u5143\u7d20\u662f\u552f\u4e00\u7684\uff0c\u8fd9\u65f6\u5019 j \u7684\u503c\u5c31\u4f1a\u7b49\u4e8e res \u7684\u957f\u5ea6\uff0c\u6839\u636e\u8fd9\u4e2a\u7279\u70b9\u8fdb\u884c\u5224\u65ad\uff0c\u5c06\u503c\u6dfb\u52a0\u8fdb res\u3002<\/p>\n<p dir=\"auto\">\u770b\u8d77\u6765\u5f88\u7b80\u5355\u5427\uff0c\u4e4b\u6240\u4ee5\u8981\u8bb2\u4e00\u8bb2\u8fd9\u4e2a\u65b9\u6cd5\uff0c\u662f\u56e0\u4e3a\u2014\u2014\u2014\u2014\u2014\u2014\u517c\u5bb9\u6027\u597d\uff01<\/p>\n<h2 dir=\"auto\">indexOf<\/h2>\n<p dir=\"auto\">\u6211\u4eec\u53ef\u4ee5\u7528 indexOf \u7b80\u5316\u5185\u5c42\u7684\u5faa\u73af\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\" data-snippet-clipboard-copy-content=\"var array = [1, 1, '1'];\n\nfunction unique(array) {\n    var res = [];\n    for (var i = 0, len = array.length; i &lt; len; i++) {\n        var current = array[i];\n        if (res.indexOf(current) === -1) {\n            res.push(current)\n        }\n    }\n    return res;\n}\n\nconsole.log(unique(array));\"><\/p>\n<pre class=\"notranslate\"><span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">array<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-kos\">[<\/span><span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-s\">'1'<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span>\n\n<span class=\"pl-k\">function<\/span> <span class=\"pl-en\">unique<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">array<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span>\n    <span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">res<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span>\n    <span class=\"pl-k\">for<\/span> <span class=\"pl-kos\">(<\/span><span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">i<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-c1\">0<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-s1\">len<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-s1\">array<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">length<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-s1\">i<\/span> <span class=\"pl-c1\">&lt;<\/span> <span class=\"pl-s1\">len<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-s1\">i<\/span><span class=\"pl-c1\">++<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span>\n        <span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">current<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-s1\">array<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-s1\">i<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span>\n        <span class=\"pl-k\">if<\/span> <span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">res<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">indexOf<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">current<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-c1\">===<\/span> <span class=\"pl-c1\">-<\/span><span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span>\n            <span class=\"pl-s1\">res<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">push<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">current<\/span><span class=\"pl-kos\">)<\/span>\n        <span class=\"pl-kos\">}<\/span>\n    <span class=\"pl-kos\">}<\/span>\n    <span class=\"pl-k\">return<\/span> <span class=\"pl-s1\">res<\/span><span class=\"pl-kos\">;<\/span>\n<span class=\"pl-kos\">}<\/span>\n\n<span class=\"pl-smi\">console<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">log<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-en\">unique<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">array<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span><\/pre>\n<\/div>\n<h2 dir=\"auto\">\u6392\u5e8f\u540e\u53bb\u91cd<\/h2>\n<p dir=\"auto\">\u8bd5\u60f3\u6211\u4eec\u5148\u5c06\u8981\u53bb\u91cd\u7684\u6570\u7ec4\u4f7f\u7528 sort \u65b9\u6cd5\u6392\u5e8f\u540e\uff0c\u76f8\u540c\u7684\u503c\u5c31\u4f1a\u88ab\u6392\u5728\u4e00\u8d77\uff0c\u7136\u540e\u6211\u4eec\u5c31\u53ef\u4ee5\u53ea\u5224\u65ad\u5f53\u524d\u5143\u7d20\u4e0e\u4e0a\u4e00\u4e2a\u5143\u7d20\u662f\u5426\u76f8\u540c\uff0c\u76f8\u540c\u5c31\u8bf4\u660e\u91cd\u590d\uff0c\u4e0d\u76f8\u540c\u5c31\u6dfb\u52a0\u8fdb res\uff0c\u8ba9\u6211\u4eec\u5199\u4e2a demo\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\" data-snippet-clipboard-copy-content=\"var array = [1, 1, '1'];\n\nfunction unique(array) {\n    var res = [];\n    var sortedArray = array.concat().sort();\n    var seen;\n    for (var i = 0, len = sortedArray.length; i &lt; len; i++) {\n        \/\/ \u5982\u679c\u662f\u7b2c\u4e00\u4e2a\u5143\u7d20\u6216\u8005\u76f8\u90bb\u7684\u5143\u7d20\u4e0d\u76f8\u540c\n        if (!i || seen !== sortedArray[i]) {\n            res.push(sortedArray[i])\n        }\n        seen = sortedArray[i];\n    }\n    return res;\n}\n\nconsole.log(unique(array));\"><\/p>\n<pre class=\"notranslate\"><span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">array<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-kos\">[<\/span><span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-s\">'1'<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span>\n\n<span class=\"pl-k\">function<\/span> <span class=\"pl-en\">unique<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">array<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span>\n    <span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">res<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span>\n    <span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">sortedArray<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-s1\">array<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">concat<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">sort<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span>\n    <span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">seen<\/span><span class=\"pl-kos\">;<\/span>\n    <span class=\"pl-k\">for<\/span> <span class=\"pl-kos\">(<\/span><span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">i<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-c1\">0<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-s1\">len<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-s1\">sortedArray<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">length<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-s1\">i<\/span> <span class=\"pl-c1\">&lt;<\/span> <span class=\"pl-s1\">len<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-s1\">i<\/span><span class=\"pl-c1\">++<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span>\n        <span class=\"pl-c\">\/\/ \u5982\u679c\u662f\u7b2c\u4e00\u4e2a\u5143\u7d20\u6216\u8005\u76f8\u90bb\u7684\u5143\u7d20\u4e0d\u76f8\u540c<\/span>\n        <span class=\"pl-k\">if<\/span> <span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">!<\/span><span class=\"pl-s1\">i<\/span> <span class=\"pl-c1\">||<\/span> <span class=\"pl-s1\">seen<\/span> <span class=\"pl-c1\">!==<\/span> <span class=\"pl-s1\">sortedArray<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-s1\">i<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span>\n            <span class=\"pl-s1\">res<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">push<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">sortedArray<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-s1\">i<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">)<\/span>\n        <span class=\"pl-kos\">}<\/span>\n        <span class=\"pl-s1\">seen<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-s1\">sortedArray<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-s1\">i<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span>\n    <span class=\"pl-kos\">}<\/span>\n    <span class=\"pl-k\">return<\/span> <span class=\"pl-s1\">res<\/span><span class=\"pl-kos\">;<\/span>\n<span class=\"pl-kos\">}<\/span>\n\n<span class=\"pl-smi\">console<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">log<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-en\">unique<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">array<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span><\/pre>\n<\/div>\n<p dir=\"auto\">\u5982\u679c\u6211\u4eec\u5bf9\u4e00\u4e2a\u5df2\u7ecf\u6392\u597d\u5e8f\u7684\u6570\u7ec4\u53bb\u91cd\uff0c\u8fd9\u79cd\u65b9\u6cd5\u6548\u7387\u80af\u5b9a\u9ad8\u4e8e\u4f7f\u7528 indexOf\u3002<\/p>\n<h2 dir=\"auto\">unique API<\/h2>\n<p dir=\"auto\">\u77e5\u9053\u4e86\u8fd9\u4e24\u79cd\u65b9\u6cd5\u540e\uff0c\u6211\u4eec\u53ef\u4ee5\u53bb\u5c1d\u8bd5\u5199\u4e00\u4e2a\u540d\u4e3a unique \u7684\u5de5\u5177\u51fd\u6570\uff0c\u6211\u4eec\u6839\u636e\u4e00\u4e2a\u53c2\u6570 isSorted \u5224\u65ad\u4f20\u5165\u7684\u6570\u7ec4\u662f\u5426\u662f\u5df2\u6392\u5e8f\u7684\uff0c\u5982\u679c\u4e3a true\uff0c\u6211\u4eec\u5c31\u5224\u65ad\u76f8\u90bb\u5143\u7d20\u662f\u5426\u76f8\u540c\uff0c\u5982\u679c\u4e3a false\uff0c\u6211\u4eec\u5c31\u4f7f\u7528 indexOf \u8fdb\u884c\u5224\u65ad<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\" data-snippet-clipboard-copy-content=\"var array1 = [1, 2, '1', 2, 1];\nvar array2 = [1, 1, '1', 2, 2];\n\n\/\/ \u7b2c\u4e00\u7248\nfunction unique(array, isSorted) {\n    var res = [];\n    var seen = [];\n\n    for (var i = 0, len = array.length; i &lt; len; i++) {\n        var value = array[i];\n        if (isSorted) {\n            if (!i || seen !== value) {\n                res.push(value)\n            }\n            seen = value;\n        }\n        else if (res.indexOf(value) === -1) {\n            res.push(value);\n        }        \n    }\n    return res;\n}\n\nconsole.log(unique(array1)); \/\/ [1, 2, &quot;1&quot;]\nconsole.log(unique(array2, true)); \/\/ [1, &quot;1&quot;, 2]\"><\/p>\n<pre class=\"notranslate\"><span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">array1<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-kos\">[<\/span><span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">2<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-s\">'1'<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">2<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span>\n<span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">array2<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-kos\">[<\/span><span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-s\">'1'<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">2<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">2<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span>\n\n<span class=\"pl-c\">\/\/ \u7b2c\u4e00\u7248<\/span>\n<span class=\"pl-k\">function<\/span> <span class=\"pl-en\">unique<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">array<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-s1\">isSorted<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span>\n    <span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">res<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span>\n    <span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">seen<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span>\n\n    <span class=\"pl-k\">for<\/span> <span class=\"pl-kos\">(<\/span><span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">i<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-c1\">0<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-s1\">len<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-s1\">array<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">length<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-s1\">i<\/span> <span class=\"pl-c1\">&lt;<\/span> <span class=\"pl-s1\">len<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-s1\">i<\/span><span class=\"pl-c1\">++<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span>\n        <span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">value<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-s1\">array<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-s1\">i<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span>\n        <span class=\"pl-k\">if<\/span> <span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">isSorted<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span>\n            <span class=\"pl-k\">if<\/span> <span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">!<\/span><span class=\"pl-s1\">i<\/span> <span class=\"pl-c1\">||<\/span> <span class=\"pl-s1\">seen<\/span> <span class=\"pl-c1\">!==<\/span> <span class=\"pl-s1\">value<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span>\n                <span class=\"pl-s1\">res<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">push<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">value<\/span><span class=\"pl-kos\">)<\/span>\n            <span class=\"pl-kos\">}<\/span>\n            <span class=\"pl-s1\">seen<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-s1\">value<\/span><span class=\"pl-kos\">;<\/span>\n        <span class=\"pl-kos\">}<\/span>\n        <span class=\"pl-k\">else<\/span> <span class=\"pl-k\">if<\/span> <span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">res<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">indexOf<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">value<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-c1\">===<\/span> <span class=\"pl-c1\">-<\/span><span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span>\n            <span class=\"pl-s1\">res<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">push<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">value<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span>\n        <span class=\"pl-kos\">}<\/span>        \n    <span class=\"pl-kos\">}<\/span>\n    <span class=\"pl-k\">return<\/span> <span class=\"pl-s1\">res<\/span><span class=\"pl-kos\">;<\/span>\n<span class=\"pl-kos\">}<\/span>\n\n<span class=\"pl-smi\">console<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">log<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-en\">unique<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">array1<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ [1, 2, \"1\"]<\/span>\n<span class=\"pl-smi\">console<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">log<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-en\">unique<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">array2<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">true<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ [1, \"1\", 2]<\/span><\/pre>\n<\/div>\n<h2 dir=\"auto\">\u4f18\u5316<\/h2>\n<p dir=\"auto\">\u5c3d\u7ba1 unqique \u5df2\u7ecf\u53ef\u4ee5\u8bd5\u4e0b\u53bb\u91cd\u529f\u80fd\uff0c\u4f46\u662f\u4e3a\u4e86\u8ba9\u8fd9\u4e2a API \u66f4\u52a0\u5f3a\u5927\uff0c\u6211\u4eec\u6765\u8003\u8651\u4e00\u4e2a\u9700\u6c42\uff1a<\/p>\n<p dir=\"auto\">\u65b0\u9700\u6c42\uff1a\u5b57\u6bcd\u7684\u5927\u5c0f\u5199\u89c6\u4e3a\u4e00\u81f4\uff0c\u6bd4\u5982&#8217;a&#8217;\u548c&#8217;A&#8217;\uff0c\u4fdd\u7559\u4e00\u4e2a\u5c31\u53ef\u4ee5\u4e86\uff01<\/p>\n<p dir=\"auto\">\u867d\u7136\u6211\u4eec\u53ef\u4ee5\u5148\u5904\u7406\u6570\u7ec4\u4e2d\u7684\u6240\u6709\u6570\u636e\uff0c\u6bd4\u5982\u5c06\u6240\u6709\u7684\u5b57\u6bcd\u8f6c\u6210\u5c0f\u5199\uff0c\u7136\u540e\u518d\u4f20\u5165unique\u51fd\u6570\uff0c\u4f46\u662f\u6709\u6ca1\u6709\u65b9\u6cd5\u53ef\u4ee5\u7701\u6389\u5904\u7406\u6570\u7ec4\u7684\u8fd9\u4e00\u904d\u5faa\u73af\uff0c\u76f4\u63a5\u5c31\u5728\u53bb\u91cd\u7684\u5faa\u73af\u4e2d\u505a\u5462\uff1f\u8ba9\u6211\u4eec\u53bb\u5b8c\u6210\u8fd9\u4e2a\u9700\u6c42\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\" data-snippet-clipboard-copy-content=\"var array3 = [1, 1, 'a', 'A', 2, 2];\n\n\/\/ \u7b2c\u4e8c\u7248\n\/\/ iteratee \u82f1\u6587\u91ca\u4e49\uff1a\u8fed\u4ee3 \u91cd\u590d\nfunction unique(array, isSorted, iteratee) {\n    var res = [];\n    var seen = [];\n\n    for (var i = 0, len = array.length; i &lt; len; i++) {\n        var value = array[i];\n        var computed = iteratee ? iteratee(value, i, array) : value;\n        if (isSorted) {\n            if (!i || seen !== computed) {\n                res.push(value)\n            }\n            seen = computed;\n        }\n        else if (iteratee) {\n            if (seen.indexOf(computed) === -1) {\n                seen.push(computed);\n                res.push(value);\n            }\n        }\n        else if (res.indexOf(value) === -1) {\n            res.push(value);\n        }        \n    }\n    return res;\n}\n\nconsole.log(unique(array3, false, function(item){\n    return typeof item == 'string' ? item.toLowerCase() : item\n})); \/\/ [1, &quot;a&quot;, 2]\"><\/p>\n<pre class=\"notranslate\"><span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">array3<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-kos\">[<\/span><span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-s\">'a'<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-s\">'A'<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">2<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">2<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span>\n\n<span class=\"pl-c\">\/\/ \u7b2c\u4e8c\u7248<\/span>\n<span class=\"pl-c\">\/\/ iteratee \u82f1\u6587\u91ca\u4e49\uff1a\u8fed\u4ee3 \u91cd\u590d<\/span>\n<span class=\"pl-k\">function<\/span> <span class=\"pl-en\">unique<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">array<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-s1\">isSorted<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-s1\">iteratee<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span>\n    <span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">res<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span>\n    <span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">seen<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span>\n\n    <span class=\"pl-k\">for<\/span> <span class=\"pl-kos\">(<\/span><span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">i<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-c1\">0<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-s1\">len<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-s1\">array<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-c1\">length<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-s1\">i<\/span> <span class=\"pl-c1\">&lt;<\/span> <span class=\"pl-s1\">len<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-s1\">i<\/span><span class=\"pl-c1\">++<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span>\n        <span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">value<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-s1\">array<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-s1\">i<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span>\n        <span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">computed<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-s1\">iteratee<\/span> ? <span class=\"pl-s1\">iteratee<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">value<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-s1\">i<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-s1\">array<\/span><span class=\"pl-kos\">)<\/span> : <span class=\"pl-s1\">value<\/span><span class=\"pl-kos\">;<\/span>\n        <span class=\"pl-k\">if<\/span> <span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">isSorted<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span>\n            <span class=\"pl-k\">if<\/span> <span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">!<\/span><span class=\"pl-s1\">i<\/span> <span class=\"pl-c1\">||<\/span> <span class=\"pl-s1\">seen<\/span> <span class=\"pl-c1\">!==<\/span> <span class=\"pl-s1\">computed<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span>\n                <span class=\"pl-s1\">res<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">push<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">value<\/span><span class=\"pl-kos\">)<\/span>\n            <span class=\"pl-kos\">}<\/span>\n            <span class=\"pl-s1\">seen<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-s1\">computed<\/span><span class=\"pl-kos\">;<\/span>\n        <span class=\"pl-kos\">}<\/span>\n        <span class=\"pl-k\">else<\/span> <span class=\"pl-k\">if<\/span> <span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">iteratee<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span>\n            <span class=\"pl-k\">if<\/span> <span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">seen<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">indexOf<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">computed<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-c1\">===<\/span> <span class=\"pl-c1\">-<\/span><span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span>\n                <span class=\"pl-s1\">seen<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">push<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">computed<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span>\n                <span class=\"pl-s1\">res<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">push<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">value<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span>\n            <span class=\"pl-kos\">}<\/span>\n        <span class=\"pl-kos\">}<\/span>\n        <span class=\"pl-k\">else<\/span> <span class=\"pl-k\">if<\/span> <span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">res<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">indexOf<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">value<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-c1\">===<\/span> <span class=\"pl-c1\">-<\/span><span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span>\n            <span class=\"pl-s1\">res<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">push<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">value<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span>\n        <span class=\"pl-kos\">}<\/span>        \n    <span class=\"pl-kos\">}<\/span>\n    <span class=\"pl-k\">return<\/span> <span class=\"pl-s1\">res<\/span><span class=\"pl-kos\">;<\/span>\n<span class=\"pl-kos\">}<\/span>\n\n<span class=\"pl-smi\">console<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">log<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-en\">unique<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">array3<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">false<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-k\">function<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">item<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">{<\/span>\n    <span class=\"pl-k\">return<\/span> <span class=\"pl-k\">typeof<\/span> <span class=\"pl-s1\">item<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-s\">'string'<\/span> ? <span class=\"pl-s1\">item<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">toLowerCase<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span> : <span class=\"pl-s1\">item<\/span>\n<span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ [1, \"a\", 2]<\/span><\/pre>\n<\/div>\n<p dir=\"auto\">\u5728\u8fd9\u4e00\u7248\u4e5f\u662f\u6700\u540e\u4e00\u7248\u7684\u5b9e\u73b0\u4e2d\uff0c\u51fd\u6570\u4f20\u9012\u4e09\u4e2a\u53c2\u6570\uff1a<\/p>\n<p dir=\"auto\">array\uff1a\u8868\u793a\u8981\u53bb\u91cd\u7684\u6570\u7ec4\uff0c\u5fc5\u586b<\/p>\n<p dir=\"auto\">isSorted\uff1a\u8868\u793a\u51fd\u6570\u4f20\u5165\u7684\u6570\u7ec4\u662f\u5426\u5df2\u6392\u8fc7\u5e8f\uff0c\u5982\u679c\u4e3a true\uff0c\u5c06\u4f1a\u91c7\u7528\u66f4\u5feb\u7684\u65b9\u6cd5\u8fdb\u884c\u53bb\u91cd<\/p>\n<p dir=\"auto\">iteratee\uff1a\u4f20\u5165\u4e00\u4e2a\u51fd\u6570\uff0c\u53ef\u4ee5\u5bf9\u6bcf\u4e2a\u5143\u7d20\u8fdb\u884c\u91cd\u65b0\u7684\u8ba1\u7b97\uff0c\u7136\u540e\u6839\u636e\u5904\u7406\u7684\u7ed3\u679c\u8fdb\u884c\u53bb\u91cd<\/p>\n<p dir=\"auto\">\u81f3\u6b64\uff0c\u6211\u4eec\u5df2\u7ecf\u4eff\u7167\u7740 underscore \u7684\u601d\u8def\u5199\u4e86\u4e00\u4e2a unique \u51fd\u6570\uff0c\u5177\u4f53\u53ef\u4ee5\u67e5\u770b <a href=\"https:\/\/github.com\/jashkenas\/underscore\/blob\/master\/underscore.js#L562\">Github<\/a>\u3002<\/p>\n<h2 dir=\"auto\">filter<\/h2>\n<p dir=\"auto\">ES5 \u63d0\u4f9b\u4e86 filter \u65b9\u6cd5\uff0c\u6211\u4eec\u53ef\u4ee5\u7528\u6765\u7b80\u5316\u5916\u5c42\u5faa\u73af\uff1a<\/p>\n<p dir=\"auto\">\u6bd4\u5982\u4f7f\u7528 indexOf \u7684\u65b9\u6cd5\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\" data-snippet-clipboard-copy-content=\"var array = [1, 2, 1, 1, '1'];\n\nfunction unique(array) {\n    var res = array.filter(function(item, index, array){\n        return array.indexOf(item) === index;\n    })\n    return res;\n}\n\nconsole.log(unique(array));\"><\/p>\n<pre class=\"notranslate\"><span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">array<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-kos\">[<\/span><span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">2<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-s\">'1'<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span>\n\n<span class=\"pl-k\">function<\/span> <span class=\"pl-en\">unique<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">array<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span>\n    <span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">res<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-s1\">array<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">filter<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-k\">function<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">item<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-s1\">index<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-s1\">array<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">{<\/span>\n        <span class=\"pl-k\">return<\/span> <span class=\"pl-s1\">array<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">indexOf<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">item<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-c1\">===<\/span> <span class=\"pl-s1\">index<\/span><span class=\"pl-kos\">;<\/span>\n    <span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">)<\/span>\n    <span class=\"pl-k\">return<\/span> <span class=\"pl-s1\">res<\/span><span class=\"pl-kos\">;<\/span>\n<span class=\"pl-kos\">}<\/span>\n\n<span class=\"pl-smi\">console<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">log<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-en\">unique<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">array<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span><\/pre>\n<\/div>\n<p dir=\"auto\">\u6392\u5e8f\u53bb\u91cd\u7684\u65b9\u6cd5\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\" data-snippet-clipboard-copy-content=\"var array = [1, 2, 1, 1, '1'];\n\nfunction unique(array) {\n    return array.concat().sort().filter(function(item, index, array){\n        return !index || item !== array[index - 1]\n    })\n}\n\nconsole.log(unique(array));\"><\/p>\n<pre class=\"notranslate\"><span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">array<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-kos\">[<\/span><span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">2<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-s\">'1'<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span>\n\n<span class=\"pl-k\">function<\/span> <span class=\"pl-en\">unique<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">array<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span>\n    <span class=\"pl-k\">return<\/span> <span class=\"pl-s1\">array<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">concat<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">sort<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">filter<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-k\">function<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">item<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-s1\">index<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-s1\">array<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">{<\/span>\n        <span class=\"pl-k\">return<\/span> <span class=\"pl-c1\">!<\/span><span class=\"pl-s1\">index<\/span> <span class=\"pl-c1\">||<\/span> <span class=\"pl-s1\">item<\/span> <span class=\"pl-c1\">!==<\/span> <span class=\"pl-s1\">array<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-s1\">index<\/span> <span class=\"pl-c1\">-<\/span> <span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">]<\/span>\n    <span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">)<\/span>\n<span class=\"pl-kos\">}<\/span>\n\n<span class=\"pl-smi\">console<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">log<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-en\">unique<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">array<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span><\/pre>\n<\/div>\n<h2 dir=\"auto\">Object \u952e\u503c\u5bf9<\/h2>\n<p dir=\"auto\">\u53bb\u91cd\u7684\u65b9\u6cd5\u4f17\u591a\uff0c\u5c3d\u7ba1\u6211\u4eec\u5df2\u7ecf\u8ddf\u7740 underscore \u5199\u4e86\u4e00\u4e2a unqiue API\uff0c\u4f46\u662f\u8ba9\u6211\u4eec\u770b\u770b\u5176\u4ed6\u7684\u65b9\u6cd5\u62d3\u5c55\u4e0b\u89c6\u91ce\uff1a<\/p>\n<p dir=\"auto\">\u8fd9\u79cd\u65b9\u6cd5\u662f\u5229\u7528\u4e00\u4e2a\u7a7a\u7684 Object \u5bf9\u8c61\uff0c\u6211\u4eec\u628a\u6570\u7ec4\u7684\u503c\u5b58\u6210 Object \u7684 key \u503c\uff0c\u6bd4\u5982 Object[value1] = true\uff0c\u5728\u5224\u65ad\u53e6\u4e00\u4e2a\u503c\u7684\u65f6\u5019\uff0c\u5982\u679c Object[value2]\u5b58\u5728\u7684\u8bdd\uff0c\u5c31\u8bf4\u660e\u8be5\u503c\u662f\u91cd\u590d\u7684\u3002\u793a\u4f8b\u4ee3\u7801\u5982\u4e0b\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\" data-snippet-clipboard-copy-content=\"var array = [1, 2, 1, 1, '1'];\n\nfunction unique(array) {\n    var obj = {};\n    return array.filter(function(item, index, array){\n        return obj.hasOwnProperty(item) ? false : (obj[item] = true)\n    })\n}\n\nconsole.log(unique(array)); \/\/ [1, 2]\"><\/p>\n<pre class=\"notranslate\"><span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">array<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-kos\">[<\/span><span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">2<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-s\">'1'<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span>\n\n<span class=\"pl-k\">function<\/span> <span class=\"pl-en\">unique<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">array<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span>\n    <span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">obj<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-kos\">{<\/span><span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">;<\/span>\n    <span class=\"pl-k\">return<\/span> <span class=\"pl-s1\">array<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">filter<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-k\">function<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">item<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-s1\">index<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-s1\">array<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">{<\/span>\n        <span class=\"pl-k\">return<\/span> <span class=\"pl-s1\">obj<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">hasOwnProperty<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">item<\/span><span class=\"pl-kos\">)<\/span> ? <span class=\"pl-c1\">false<\/span> : <span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">obj<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-s1\">item<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-c1\">true<\/span><span class=\"pl-kos\">)<\/span>\n    <span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">)<\/span>\n<span class=\"pl-kos\">}<\/span>\n\n<span class=\"pl-smi\">console<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">log<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-en\">unique<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">array<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ [1, 2]<\/span><\/pre>\n<\/div>\n<p dir=\"auto\">\u6211\u4eec\u53ef\u4ee5\u53d1\u73b0\uff0c\u662f\u6709\u95ee\u9898\u7684\uff0c\u56e0\u4e3a 1 \u548c &#8216;1&#8217; \u662f\u4e0d\u540c\u7684\uff0c\u4f46\u662f\u8fd9\u79cd\u65b9\u6cd5\u4f1a\u5224\u65ad\u4e3a\u540c\u4e00\u4e2a\u503c\uff0c\u8fd9\u662f\u56e0\u4e3a\u5bf9\u8c61\u7684\u952e\u503c\u53ea\u80fd\u662f\u5b57\u7b26\u4e32\uff0c\u6240\u4ee5\u6211\u4eec\u53ef\u4ee5\u4f7f\u7528 <code class=\"notranslate\">typeof item + item<\/code> \u62fc\u6210\u5b57\u7b26\u4e32\u4f5c\u4e3a key \u503c\u6765\u907f\u514d\u8fd9\u4e2a\u95ee\u9898\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\" data-snippet-clipboard-copy-content=\"var array = [1, 2, 1, 1, '1'];\n\nfunction unique(array) {\n    var obj = {};\n    return array.filter(function(item, index, array){\n        return obj.hasOwnProperty(typeof item + item) ? false : (obj[typeof item + item] = true)\n    })\n}\n\nconsole.log(unique(array)); \/\/ [1, 2, &quot;1&quot;]\"><\/p>\n<pre class=\"notranslate\"><span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">array<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-kos\">[<\/span><span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">2<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-s\">'1'<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span>\n\n<span class=\"pl-k\">function<\/span> <span class=\"pl-en\">unique<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">array<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span>\n    <span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">obj<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-kos\">{<\/span><span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">;<\/span>\n    <span class=\"pl-k\">return<\/span> <span class=\"pl-s1\">array<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">filter<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-k\">function<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">item<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-s1\">index<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-s1\">array<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">{<\/span>\n        <span class=\"pl-k\">return<\/span> <span class=\"pl-s1\">obj<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">hasOwnProperty<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-k\">typeof<\/span> <span class=\"pl-s1\">item<\/span> <span class=\"pl-c1\">+<\/span> <span class=\"pl-s1\">item<\/span><span class=\"pl-kos\">)<\/span> ? <span class=\"pl-c1\">false<\/span> : <span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">obj<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-k\">typeof<\/span> <span class=\"pl-s1\">item<\/span> <span class=\"pl-c1\">+<\/span> <span class=\"pl-s1\">item<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-c1\">true<\/span><span class=\"pl-kos\">)<\/span>\n    <span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">)<\/span>\n<span class=\"pl-kos\">}<\/span>\n\n<span class=\"pl-smi\">console<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">log<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-en\">unique<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">array<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ [1, 2, \"1\"]<\/span><\/pre>\n<\/div>\n<p dir=\"auto\">\u7136\u800c\uff0c\u5373\u4fbf\u5982\u6b64\uff0c\u6211\u4eec\u4f9d\u7136\u65e0\u6cd5\u6b63\u786e\u533a\u5206\u51fa\u4e24\u4e2a\u5bf9\u8c61\uff0c\u6bd4\u5982 {value: 1} \u548c {value: 2}\uff0c\u56e0\u4e3a <code class=\"notranslate\">typeof item + item<\/code> \u7684\u7ed3\u679c\u90fd\u4f1a\u662f <code class=\"notranslate\">object[object Object]<\/code>\uff0c\u4e0d\u8fc7\u6211\u4eec\u53ef\u4ee5\u4f7f\u7528 JSON.stringify \u5c06\u5bf9\u8c61\u5e8f\u5217\u5316\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\" data-snippet-clipboard-copy-content=\"var array = [{value: 1}, {value: 1}, {value: 2}];\n\nfunction unique(array) {\n    var obj = {};\n    return array.filter(function(item, index, array){\n        console.log(typeof item + JSON.stringify(item))\n        return obj.hasOwnProperty(typeof item + JSON.stringify(item)) ? false : (obj[typeof item + JSON.stringify(item)] = true)\n    })\n}\n\nconsole.log(unique(array)); \/\/ [{value: 1}, {value: 2}]\"><\/p>\n<pre class=\"notranslate\"><span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">array<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-kos\">[<\/span><span class=\"pl-kos\">{<\/span><span class=\"pl-c1\">value<\/span>: <span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-kos\">{<\/span><span class=\"pl-c1\">value<\/span>: <span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-kos\">{<\/span><span class=\"pl-c1\">value<\/span>: <span class=\"pl-c1\">2<\/span><span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span>\n\n<span class=\"pl-k\">function<\/span> <span class=\"pl-en\">unique<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">array<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span>\n    <span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">obj<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-kos\">{<\/span><span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">;<\/span>\n    <span class=\"pl-k\">return<\/span> <span class=\"pl-s1\">array<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">filter<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-k\">function<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">item<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-s1\">index<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-s1\">array<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">{<\/span>\n        <span class=\"pl-smi\">console<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">log<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-k\">typeof<\/span> <span class=\"pl-s1\">item<\/span> <span class=\"pl-c1\">+<\/span> <span class=\"pl-c1\">JSON<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">stringify<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">item<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">)<\/span>\n        <span class=\"pl-k\">return<\/span> <span class=\"pl-s1\">obj<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">hasOwnProperty<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-k\">typeof<\/span> <span class=\"pl-s1\">item<\/span> <span class=\"pl-c1\">+<\/span> <span class=\"pl-c1\">JSON<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">stringify<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">item<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">)<\/span> ? <span class=\"pl-c1\">false<\/span> : <span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">obj<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-k\">typeof<\/span> <span class=\"pl-s1\">item<\/span> <span class=\"pl-c1\">+<\/span> <span class=\"pl-c1\">JSON<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">stringify<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">item<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">]<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-c1\">true<\/span><span class=\"pl-kos\">)<\/span>\n    <span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">)<\/span>\n<span class=\"pl-kos\">}<\/span>\n\n<span class=\"pl-smi\">console<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">log<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-en\">unique<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">array<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ [{value: 1}, {value: 2}]<\/span><\/pre>\n<\/div>\n<p dir=\"auto\">\u770b\u4f3c\u5df2\u7ecf\u4e07\u65e0\u4e00\u5931\uff0c\u4f46\u8003\u8651\u5230 <code class=\"notranslate\">JSON.stringify<\/code> \u4efb\u4f55\u4e00\u4e2a\u6b63\u5219\u8868\u8fbe\u5f0f\u7684\u7ed3\u679c\u90fd\u662f <code class=\"notranslate\">{}<\/code>\uff0c\u6240\u4ee5\u8fd9\u4e2a\u65b9\u6cd5\u5e76\u4e0d\u9002\u7528\u4e8e\u5904\u7406\u6b63\u5219\u8868\u8fbe\u5f0f\u53bb\u91cd\u3002(\u5f15\u7528<a href=\"https:\/\/github.com\/mqyqingfeng\/Blog\/issues\/212\" data-hovercard-type=\"issue\" data-hovercard-url=\"\/mqyqingfeng\/Blog\/issues\/212\/hovercard\">\u52d8\u8bef<\/a> )<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\" data-snippet-clipboard-copy-content=\"console.log(JSON.stringify(\/a\/)); \/\/ {}\nconsole.log(JSON.stringify(\/b\/)); \/\/ {}\"><\/p>\n<pre class=\"notranslate\"><span class=\"pl-smi\">console<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">log<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">JSON<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">stringify<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-pds\"><span class=\"pl-c1\">\/<\/span>a<span class=\"pl-c1\">\/<\/span><\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ {}<\/span>\n<span class=\"pl-smi\">console<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">log<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">JSON<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">stringify<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-pds\"><span class=\"pl-c1\">\/<\/span>b<span class=\"pl-c1\">\/<\/span><\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ {}<\/span><\/pre>\n<\/div>\n<h2 dir=\"auto\">ES6<\/h2>\n<p dir=\"auto\">\u968f\u7740 ES6 \u7684\u5230\u6765\uff0c\u53bb\u91cd\u7684\u65b9\u6cd5\u53c8\u6709\u4e86\u8fdb\u5c55\uff0c\u6bd4\u5982\u6211\u4eec\u53ef\u4ee5\u4f7f\u7528 Set \u548c Map \u6570\u636e\u7ed3\u6784\uff0c\u4ee5 Set \u4e3a\u4f8b\uff0cES6 \u63d0\u4f9b\u4e86\u65b0\u7684\u6570\u636e\u7ed3\u6784 Set\u3002\u5b83\u7c7b\u4f3c\u4e8e\u6570\u7ec4\uff0c\u4f46\u662f\u6210\u5458\u7684\u503c\u90fd\u662f\u552f\u4e00\u7684\uff0c\u6ca1\u6709\u91cd\u590d\u7684\u503c\u3002<\/p>\n<p dir=\"auto\">\u662f\u4e0d\u662f\u611f\u89c9\u5c31\u50cf\u662f\u4e3a\u53bb\u91cd\u800c\u51c6\u5907\u7684\uff1f\u8ba9\u6211\u4eec\u6765\u5199\u4e00\u7248\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\" data-snippet-clipboard-copy-content=\"var array = [1, 2, 1, 1, '1'];\n\nfunction unique(array) {\n   return Array.from(new Set(array));\n}\n\nconsole.log(unique(array)); \/\/ [1, 2, &quot;1&quot;]\"><\/p>\n<pre class=\"notranslate\"><span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">array<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-kos\">[<\/span><span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">2<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-s\">'1'<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span>\n\n<span class=\"pl-k\">function<\/span> <span class=\"pl-en\">unique<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">array<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span>\n   <span class=\"pl-k\">return<\/span> <span class=\"pl-v\">Array<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">from<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-k\">new<\/span> <span class=\"pl-v\">Set<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">array<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span>\n<span class=\"pl-kos\">}<\/span>\n\n<span class=\"pl-smi\">console<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">log<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-en\">unique<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">array<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ [1, 2, \"1\"]<\/span><\/pre>\n<\/div>\n<p dir=\"auto\">\u751a\u81f3\u53ef\u4ee5\u518d\u7b80\u5316\u4e0b\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\" data-snippet-clipboard-copy-content=\"function unique(array) {\n    return [...new Set(array)];\n}\"><\/p>\n<pre class=\"notranslate\"><span class=\"pl-k\">function<\/span> <span class=\"pl-en\">unique<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">array<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span>\n    <span class=\"pl-k\">return<\/span> <span class=\"pl-kos\">[<\/span>...<span class=\"pl-k\">new<\/span> <span class=\"pl-v\">Set<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">array<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span>\n<span class=\"pl-kos\">}<\/span><\/pre>\n<\/div>\n<p dir=\"auto\">\u8fd8\u53ef\u4ee5\u518d\u7b80\u5316\u4e0b\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\" data-snippet-clipboard-copy-content=\"var unique = (a) =&gt; [...new Set(a)]\">\n<pre class=\"notranslate\"><span class=\"pl-k\">var<\/span> <span class=\"pl-en\">unique<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">a<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-c1\">=&gt;<\/span> <span class=\"pl-kos\">[<\/span>...<span class=\"pl-k\">new<\/span> <span class=\"pl-v\">Set<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">a<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">]<\/span><\/pre>\n<\/div>\n<p dir=\"auto\">\u6b64\u5916\uff0c\u5982\u679c\u7528 Map \u7684\u8bdd\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\" data-snippet-clipboard-copy-content=\"function unique (arr) {\n    const seen = new Map()\n    return arr.filter((a) =&gt; !seen.has(a) &amp;&amp; seen.set(a, 1))\n}\"><\/p>\n<pre class=\"notranslate\"><span class=\"pl-k\">function<\/span> <span class=\"pl-en\">unique<\/span> <span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">arr<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span>\n    <span class=\"pl-k\">const<\/span> <span class=\"pl-s1\">seen<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-k\">new<\/span> <span class=\"pl-v\">Map<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">)<\/span>\n    <span class=\"pl-k\">return<\/span> <span class=\"pl-s1\">arr<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">filter<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">a<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-c1\">=&gt;<\/span> <span class=\"pl-c1\">!<\/span><span class=\"pl-s1\">seen<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">has<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">a<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-c1\">&amp;&amp;<\/span> <span class=\"pl-s1\">seen<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">set<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">a<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">)<\/span>\n<span class=\"pl-kos\">}<\/span><\/pre>\n<\/div>\n<h2 dir=\"auto\">JavaScript \u7684\u8fdb\u5316<\/h2>\n<p dir=\"auto\">\u6211\u4eec\u53ef\u4ee5\u770b\u5230\uff0c\u53bb\u91cd\u65b9\u6cd5\u4ece\u539f\u59cb\u7684 14 \u884c\u4ee3\u7801\u5230 ES6 \u7684 1 \u884c\u4ee3\u7801\uff0c\u5176\u5b9e\u4e5f\u8bf4\u660e\u4e86 JavaScript \u8fd9\u95e8\u8bed\u8a00\u5728\u4e0d\u505c\u7684\u8fdb\u6b65\uff0c\u76f8\u4fe1\u4ee5\u540e\u7684\u5f00\u53d1\u4e5f\u4f1a\u8d8a\u6765\u8d8a\u9ad8\u6548\u3002<\/p>\n<h2 dir=\"auto\">\u7279\u6b8a\u7c7b\u578b\u6bd4\u8f83<\/h2>\n<p dir=\"auto\">\u53bb\u91cd\u7684\u65b9\u6cd5\u5c31\u5230\u6b64\u7ed3\u675f\u4e86\uff0c\u7136\u800c\u8981\u53bb\u91cd\u7684\u5143\u7d20\u7c7b\u578b\u53ef\u80fd\u662f\u591a\u79cd\u591a\u6837\uff0c\u9664\u4e86\u4f8b\u5b50\u4e2d\u7b80\u5355\u7684 1 \u548c &#8216;1&#8217; \u4e4b\u5916\uff0c\u5176\u5b9e\u8fd8\u6709 null\u3001undefined\u3001NaN\u3001\u5bf9\u8c61\u7b49\uff0c\u90a3\u4e48\u5bf9\u4e8e\u8fd9\u4e9b\u5143\u7d20\uff0c\u4e4b\u524d\u7684\u8fd9\u4e9b\u65b9\u6cd5\u7684\u53bb\u91cd\u7ed3\u679c\u53c8\u662f\u600e\u6837\u5462\uff1f<\/p>\n<p dir=\"auto\">\u5728\u6b64\u4e4b\u524d\uff0c\u5148\u8ba9\u6211\u4eec\u5148\u770b\u51e0\u4e2a\u4f8b\u5b50\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\" data-snippet-clipboard-copy-content=\"var str1 = '1';\nvar str2 = new String('1');\n\nconsole.log(str1 == str2); \/\/ true\nconsole.log(str1 === str2); \/\/ false\n\nconsole.log(null == null); \/\/ true\nconsole.log(null === null); \/\/ true\n\nconsole.log(undefined == undefined); \/\/ true\nconsole.log(undefined === undefined); \/\/ true\n\nconsole.log(NaN == NaN); \/\/ false\nconsole.log(NaN === NaN); \/\/ false\n\nconsole.log(\/a\/ == \/a\/); \/\/ false\nconsole.log(\/a\/ === \/a\/); \/\/ false\n\nconsole.log({} == {}); \/\/ false\nconsole.log({} === {}); \/\/ false\"><\/p>\n<pre class=\"notranslate\"><span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">str1<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-s\">'1'<\/span><span class=\"pl-kos\">;<\/span>\n<span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">str2<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-k\">new<\/span> <span class=\"pl-v\">String<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s\">'1'<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span>\n\n<span class=\"pl-smi\">console<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">log<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">str1<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-s1\">str2<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ true<\/span>\n<span class=\"pl-smi\">console<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">log<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">str1<\/span> <span class=\"pl-c1\">===<\/span> <span class=\"pl-s1\">str2<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ false<\/span>\n\n<span class=\"pl-smi\">console<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">log<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">null<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-c1\">null<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ true<\/span>\n<span class=\"pl-smi\">console<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">log<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">null<\/span> <span class=\"pl-c1\">===<\/span> <span class=\"pl-c1\">null<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ true<\/span>\n\n<span class=\"pl-smi\">console<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">log<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">undefined<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-c1\">undefined<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ true<\/span>\n<span class=\"pl-smi\">console<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">log<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-c1\">undefined<\/span> <span class=\"pl-c1\">===<\/span> <span class=\"pl-c1\">undefined<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ true<\/span>\n\n<span class=\"pl-smi\">console<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">log<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-v\">NaN<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-v\">NaN<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ false<\/span>\n<span class=\"pl-smi\">console<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">log<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-v\">NaN<\/span> <span class=\"pl-c1\">===<\/span> <span class=\"pl-v\">NaN<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ false<\/span>\n\n<span class=\"pl-smi\">console<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">log<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-pds\"><span class=\"pl-c1\">\/<\/span>a<span class=\"pl-c1\">\/<\/span><\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-pds\"><span class=\"pl-c1\">\/<\/span>a<span class=\"pl-c1\">\/<\/span><\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ false<\/span>\n<span class=\"pl-smi\">console<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">log<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-pds\"><span class=\"pl-c1\">\/<\/span>a<span class=\"pl-c1\">\/<\/span><\/span> <span class=\"pl-c1\">===<\/span> <span class=\"pl-pds\"><span class=\"pl-c1\">\/<\/span>a<span class=\"pl-c1\">\/<\/span><\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ false<\/span>\n\n<span class=\"pl-smi\">console<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">log<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">{<\/span><span class=\"pl-kos\">}<\/span> <span class=\"pl-c1\">==<\/span> <span class=\"pl-kos\">{<\/span><span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ false<\/span>\n<span class=\"pl-smi\">console<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">log<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">{<\/span><span class=\"pl-kos\">}<\/span> <span class=\"pl-c1\">===<\/span> <span class=\"pl-kos\">{<\/span><span class=\"pl-kos\">}<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ false<\/span><\/pre>\n<\/div>\n<p dir=\"auto\">\u90a3\u4e48\uff0c\u5bf9\u4e8e\u8fd9\u6837\u4e00\u4e2a\u6570\u7ec4<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\" data-snippet-clipboard-copy-content=\"var array = [1, 1, '1', '1', null, null, undefined, undefined, new String('1'), new String('1'), \/a\/, \/a\/, NaN, NaN];\">\n<pre class=\"notranslate\"><span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">array<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-kos\">[<\/span><span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-s\">'1'<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-s\">'1'<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">null<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">null<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">undefined<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">undefined<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-k\">new<\/span> <span class=\"pl-v\">String<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s\">'1'<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-k\">new<\/span> <span class=\"pl-v\">String<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s\">'1'<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-pds\"><span class=\"pl-c1\">\/<\/span>a<span class=\"pl-c1\">\/<\/span><\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-pds\"><span class=\"pl-c1\">\/<\/span>a<span class=\"pl-c1\">\/<\/span><\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-v\">NaN<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-v\">NaN<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span><\/pre>\n<\/div>\n<p dir=\"auto\">\u4ee5\u4e0a\u5404\u79cd\u65b9\u6cd5\u53bb\u91cd\u7684\u7ed3\u679c\u5230\u5e95\u662f\u4ec0\u4e48\u6837\u7684\u5462\uff1f<\/p>\n<p dir=\"auto\">\u6211\u7279\u5730\u6574\u7406\u4e86\u4e00\u4e2a\u5217\u8868\uff0c\u6211\u4eec\u91cd\u70b9\u5173\u6ce8\u4e0b\u5bf9\u8c61\u548c NaN \u7684\u53bb\u91cd\u60c5\u51b5\uff1a<\/p>\n<table role=\"table\">\n<tbody>\n<tr>\n<th>\u65b9\u6cd5<\/th>\n<th>\u7ed3\u679c<\/th>\n<th>\u8bf4\u660e<\/th>\n<\/tr>\n<tr>\n<td>for\u5faa\u73af<\/td>\n<td>[1, &#8220;1&#8221;, null, undefined, String, String, \/a\/, \/a\/, NaN, NaN]<\/td>\n<td>\u5bf9\u8c61\u548c NaN \u4e0d\u53bb\u91cd<\/td>\n<\/tr>\n<tr>\n<td>indexOf<\/td>\n<td>[1, &#8220;1&#8221;, null, undefined, String, String, \/a\/, \/a\/, NaN, NaN]<\/td>\n<td>\u5bf9\u8c61\u548c NaN \u4e0d\u53bb\u91cd<\/td>\n<\/tr>\n<tr>\n<td>sort<\/td>\n<td>[\/a\/, \/a\/, &#8220;1&#8221;, 1, String, 1, String, NaN, NaN, null, undefined]<\/td>\n<td>\u5bf9\u8c61\u548c NaN \u4e0d\u53bb\u91cd \u6570\u5b57 1 \u4e5f\u4e0d\u53bb\u91cd<\/td>\n<\/tr>\n<tr>\n<td>filter + indexOf<\/td>\n<td>[1, &#8220;1&#8221;, null, undefined, String, String, \/a\/, \/a\/]<\/td>\n<td>\u5bf9\u8c61\u4e0d\u53bb\u91cd NaN \u4f1a\u88ab\u5ffd\u7565\u6389<\/td>\n<\/tr>\n<tr>\n<td>filter + sort<\/td>\n<td>[\/a\/, \/a\/, &#8220;1&#8221;, 1, String, 1, String, NaN, NaN, null, undefined]<\/td>\n<td>\u5bf9\u8c61\u548c NaN \u4e0d\u53bb\u91cd \u6570\u5b57 1 \u4e0d\u53bb\u91cd<\/td>\n<\/tr>\n<tr>\n<td>\u4f18\u5316\u540e\u7684\u952e\u503c\u5bf9\u65b9\u6cd5<\/td>\n<td>[1, &#8220;1&#8221;, null, undefined, String, \/a\/, NaN]<\/td>\n<td>\u5168\u90e8\u53bb\u91cd<\/td>\n<\/tr>\n<tr>\n<td>Set<\/td>\n<td>[1, &#8220;1&#8221;, null, undefined, String, String, \/a\/, \/a\/, NaN]<\/td>\n<td>\u5bf9\u8c61\u4e0d\u53bb\u91cd NaN \u53bb\u91cd<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p dir=\"auto\">\u8fd9\u91cc\u518d\u6b21\u58f0\u660e\u4e00\u4e0b\uff0c\u952e\u503c\u5bf9\u65b9\u6cd5\u4e0d\u80fd\u53bb\u91cd\u6b63\u5219\u8868\u8fbe\u5f0f\u3002<\/p>\n<p dir=\"auto\">\u60f3\u4e86\u89e3\u4e3a\u4ec0\u4e48\u4f1a\u51fa\u73b0\u4ee5\u4e0a\u7684\u7ed3\u679c\uff0c\u770b\u4e24\u4e2a demo \u4fbf\u80fd\u660e\u767d\uff1a<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\" data-snippet-clipboard-copy-content=\"\/\/ demo1\nvar arr = [1, 2, NaN];\narr.indexOf(NaN); \/\/ -1\"><\/p>\n<pre class=\"notranslate\"><span class=\"pl-c\">\/\/ demo1<\/span>\n<span class=\"pl-k\">var<\/span> <span class=\"pl-s1\">arr<\/span> <span class=\"pl-c1\">=<\/span> <span class=\"pl-kos\">[<\/span><span class=\"pl-c1\">1<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-c1\">2<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-v\">NaN<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">;<\/span>\n<span class=\"pl-s1\">arr<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">indexOf<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-v\">NaN<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span> <span class=\"pl-c\">\/\/ -1<\/span><\/pre>\n<\/div>\n<p dir=\"auto\">indexOf \u5e95\u5c42\u8fd8\u662f\u4f7f\u7528 === \u8fdb\u884c\u5224\u65ad\uff0c\u56e0\u4e3a NaN === NaN\u7684\u7ed3\u679c\u4e3a false\uff0c\u6240\u4ee5\u4f7f\u7528 indexOf \u67e5\u627e\u4e0d\u5230 NaN \u5143\u7d20<\/p>\n<div class=\"highlight highlight-source-js notranslate position-relative overflow-auto\" dir=\"auto\" data-snippet-clipboard-copy-content=\"\/\/ demo2\nfunction unique(array) {\n   return Array.from(new Set(array));\n}\nconsole.log(unique([NaN, NaN])) \/\/ [NaN]\"><\/p>\n<pre class=\"notranslate\"><span class=\"pl-c\">\/\/ demo2<\/span>\n<span class=\"pl-k\">function<\/span> <span class=\"pl-en\">unique<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">array<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-kos\">{<\/span>\n   <span class=\"pl-k\">return<\/span> <span class=\"pl-v\">Array<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">from<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-k\">new<\/span> <span class=\"pl-v\">Set<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-s1\">array<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">;<\/span>\n<span class=\"pl-kos\">}<\/span>\n<span class=\"pl-smi\">console<\/span><span class=\"pl-kos\">.<\/span><span class=\"pl-en\">log<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-en\">unique<\/span><span class=\"pl-kos\">(<\/span><span class=\"pl-kos\">[<\/span><span class=\"pl-v\">NaN<\/span><span class=\"pl-kos\">,<\/span> <span class=\"pl-v\">NaN<\/span><span class=\"pl-kos\">]<\/span><span class=\"pl-kos\">)<\/span><span class=\"pl-kos\">)<\/span> <span class=\"pl-c\">\/\/ [NaN]<\/span><\/pre>\n<\/div>\n<p dir=\"auto\">Set \u8ba4\u4e3a\u5c3d\u7ba1 NaN === NaN \u4e3a false\uff0c\u4f46\u662f\u8fd9\u4e24\u4e2a\u5143\u7d20\u662f\u91cd\u590d\u7684\u3002<\/p>\n<h2 dir=\"auto\">\u5199\u5728\u6700\u540e<\/h2>\n<p dir=\"auto\">\u867d\u7136\u53bb\u91cd\u7684\u7ed3\u679c\u6709\u6240\u4e0d\u540c\uff0c\u4f46\u66f4\u91cd\u8981\u7684\u662f\u8ba9\u6211\u4eec\u77e5\u9053\u5728\u5408\u9002\u7684\u573a\u666f\u8981\u9009\u62e9\u5408\u9002\u7684\u65b9\u6cd5\u3002<\/p>\n<h2 dir=\"auto\">\u4e13\u9898\u7cfb\u5217<\/h2>\n<p dir=\"auto\">JavaScript\u4e13\u9898\u7cfb\u5217\u76ee\u5f55\u5730\u5740\uff1a<a href=\"https:\/\/github.com\/mqyqingfeng\/Blog\">https:\/\/github.com\/mqyqingfeng\/Blog<\/a>\u3002<\/p>\n<p dir=\"auto\">JavaScript\u4e13\u9898\u7cfb\u5217\u9884\u8ba1\u5199\u4e8c\u5341\u7bc7\u5de6\u53f3\uff0c\u4e3b\u8981\u7814\u7a76\u65e5\u5e38\u5f00\u53d1\u4e2d\u4e00\u4e9b\u529f\u80fd\u70b9\u7684\u5b9e\u73b0\uff0c\u6bd4\u5982\u9632\u6296\u3001\u8282\u6d41\u3001\u53bb\u91cd\u3001\u7c7b\u578b\u5224\u65ad\u3001\u62f7\u8d1d\u3001\u6700\u503c\u3001\u6241\u5e73\u3001\u67ef\u91cc\u3001\u9012\u5f52\u3001\u4e71\u5e8f\u3001\u6392\u5e8f\u7b49\uff0c\u7279\u70b9\u662f\u7814(chao)\u7a76(xi) underscore \u548c jQuery \u7684\u5b9e\u73b0\u65b9\u5f0f\u3002<\/p>\n<\/td>\n<p>\u6587\u7ae0\u8f6c\u8f7d\u81ea<a href='https:\/\/github.com\/mqyqingfeng\/Blog\/issues\/27'>https:\/\/github.com\/mqyqingfeng\/Blog\/issues\/27<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u524d\u8a00 \u6570\u7ec4\u53bb\u91cd\u65b9\u6cd5\u8001\u751f\u5e38\u8c08\uff0c\u65e2\u7136\u662f\u5e38\u8c08\uff0c\u6211\u4e5f\u6765\u8c08\u8c08\u3002 \u53cc\u5c42\u5faa\u73af \u4e5f\u8bb8\u6211\u4eec\u9996\u5148\u60f3\u5230\u7684\u662f\u4f7f\u7528 indexOf \u6765\u5faa\u73af\u5224\u65ad\u4e00\u904d\uff0c\u4f46\u5728\u8fd9\u4e2a\u65b9\u6cd5\u4e4b\u524d\uff0c\u8ba9\u6211\u4eec\u5148\u770b\u770b\u6700\u539f\u59cb\u7684&#8230;<\/p>\n<p class=\"read-more\"><a class=\"btn btn-default\" href=\"https:\/\/www.lccc.top\/?p=1381\"> Read More<span class=\"screen-reader-text\">  Read More<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-1381","post","type-post","status-publish","format-standard","hentry","category-learn"],"_links":{"self":[{"href":"https:\/\/www.lccc.top\/index.php?rest_route=\/wp\/v2\/posts\/1381"}],"collection":[{"href":"https:\/\/www.lccc.top\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.lccc.top\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.lccc.top\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.lccc.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1381"}],"version-history":[{"count":1,"href":"https:\/\/www.lccc.top\/index.php?rest_route=\/wp\/v2\/posts\/1381\/revisions"}],"predecessor-version":[{"id":1500,"href":"https:\/\/www.lccc.top\/index.php?rest_route=\/wp\/v2\/posts\/1381\/revisions\/1500"}],"wp:attachment":[{"href":"https:\/\/www.lccc.top\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1381"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.lccc.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1381"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.lccc.top\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1381"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}