{"id":1368,"date":"2024-06-02T22:24:52","date_gmt":"2024-06-02T22:24:52","guid":{"rendered":""},"modified":"2024-06-05T03:09:46","modified_gmt":"2024-06-04T19:09:46","slug":"underscore-%e7%b3%bb%e5%88%97%e4%b9%8b%e5%86%85%e9%83%a8%e5%87%bd%e6%95%b0-restargs","status":"publish","type":"post","link":"https:\/\/www.lccc.top\/?p=1368","title":{"rendered":"underscore \u7cfb\u5217\u4e4b\u5185\u90e8\u51fd\u6570 restArgs"},"content":{"rendered":"\n

partial<\/h2>\n

\u5728\u300a JavaScript \u4e13\u9898\u4e4b\u504f\u51fd\u6570\u300b<\/a>\u4e2d\uff0c\u6211\u4eec\u5199\u4e86\u4e00\u4e2a partial \u51fd\u6570\uff0c\u7528\u6765\u56fa\u5b9a\u51fd\u6570\u7684\u90e8\u5206\u53c2\u6570\uff0c\u5b9e\u73b0\u4ee3\u7801\u5982\u4e0b\uff1a<\/p>\n

<\/p>\n
\/\/ \u8fd9\u662f\u6587\u7ae0\u4e2d\u7684\u7b2c\u4e00\u7248<\/span>\nfunction<\/span> partial<\/span>(<\/span>fn<\/span>)<\/span> {<\/span>\n    var<\/span> args<\/span> =<\/span> [<\/span>]<\/span>.<\/span>slice<\/span>.<\/span>call<\/span>(<\/span>arguments<\/span>,<\/span> 1<\/span>)<\/span>;<\/span>\n    return<\/span> function<\/span>(<\/span>)<\/span> {<\/span>\n        var<\/span> newArgs<\/span> =<\/span> args<\/span>.<\/span>concat<\/span>(<\/span>[<\/span>]<\/span>.<\/span>slice<\/span>.<\/span>call<\/span>(<\/span>arguments<\/span>)<\/span>)<\/span>;<\/span>\n        return<\/span> fn<\/span>.<\/span>apply<\/span>(<\/span>this<\/span>,<\/span> newArgs<\/span>)<\/span>;<\/span>\n    }<\/span>;<\/span>\n}<\/span>;<\/span><\/pre>\n<\/div>\n
rest parameter<\/h2>\n
ES6 \u4e3a\u6211\u4eec\u63d0\u4f9b\u4e86\u5269\u4f59\u53c2\u6570\uff08rest parameter\uff09\u8bed\u6cd5\uff0c\u5141\u8bb8\u6211\u4eec\u5c06\u4e00\u4e2a\u4e0d\u5b9a\u6570\u91cf\u7684\u53c2\u6570\u8868\u793a\u4e3a\u4e00\u4e2a\u6570\u7ec4\u3002<\/p>\n
<\/p>\n
function<\/span> fn<\/span>(<\/span>a<\/span>,<\/span> b<\/span>,<\/span> ...args<\/span>)<\/span> {<\/span>\n   console<\/span>.<\/span>log<\/span>(<\/span>args<\/span>)<\/span>;<\/span> \/\/ [3, 4, 5]<\/span>\n}<\/span>\n\nfn<\/span>(<\/span>1<\/span>,<\/span> 2<\/span>,<\/span> 3<\/span>,<\/span> 4<\/span>,<\/span> 5<\/span>)<\/span><\/pre>\n<\/div>\n
\u6211\u4eec\u53ef\u4ee5\u5229\u7528\u8fd9\u4e00\u7279\u6027\u7b80\u5316 partial \u5b9e\u73b0\u7684\u4ee3\u7801\uff1a<\/p>\n
<\/p>\n
function<\/span> partial<\/span>(<\/span>fn<\/span>,<\/span> ...args<\/span>)<\/span> {<\/span>\n    return<\/span> function<\/span>(<\/span>...partialArgs<\/span>)<\/span> {<\/span>\n        var<\/span> newArgs<\/span> =<\/span> args<\/span>.<\/span>concat<\/span>(<\/span>partialArgs<\/span>)<\/span>;<\/span>\n        return<\/span> fn<\/span>.<\/span>apply<\/span>(<\/span>this<\/span>,<\/span> newArgs<\/span>)<\/span>;<\/span>\n    }<\/span>;<\/span>\n}<\/span>;<\/span><\/pre>\n<\/div>\n
\u5199\u4e2a demo\uff0c\u6d4b\u8bd5\u4e00\u4e0b\uff1a<\/p>\n
<\/p>\n
function<\/span> add<\/span>(<\/span>a<\/span>,<\/span> b<\/span>)<\/span> {<\/span>\n    return<\/span> a<\/span> +<\/span> b<\/span>;<\/span>\n}<\/span>\n\nvar<\/span> addOne<\/span> =<\/span> partial<\/span>(<\/span>add<\/span>,<\/span> 1<\/span>)<\/span>;<\/span>\n\nconsole<\/span>.<\/span>log<\/span>(<\/span>addOne<\/span>(<\/span>2<\/span>)<\/span>)<\/span>;<\/span> \/\/ 3<\/span><\/pre>\n<\/div>\n
restArgs<\/h2>\n
\u5982\u679c\u4e0d\u4f7f\u7528 … \u62d3\u5c55\u64cd\u4f5c\u7b26\uff0c\u4ec5\u7528 ES5 \u7684\u5185\u5bb9\uff0c\u8be5\u600e\u4e48\u5b9e\u73b0\u5462\uff1f<\/p>\n
\u6211\u4eec\u53ef\u4ee5\u5199\u4e00\u4e2a restArgs \u51fd\u6570\uff0c\u4f20\u5165\u4e00\u4e2a\u51fd\u6570\uff0c\u4f7f\u7528\u51fd\u6570\u7684\u6700\u540e\u4e00\u4e2a\u53c2\u6570\u50a8\u5b58\u5269\u4e0b\u7684\u51fd\u6570\u53c2\u6570\uff0c\u4f7f\u7528\u6548\u679c\u5982\u4e0b\uff1a<\/p>\n
<\/p>\n
var<\/span> func<\/span> =<\/span> restArgs<\/span>(<\/span>function<\/span>(<\/span>a<\/span>,<\/span> b<\/span>,<\/span> c<\/span>)<\/span>{<\/span>\n    console<\/span>.<\/span>log<\/span>(<\/span>c<\/span>)<\/span>;<\/span> \/\/ [3, 4, 5]<\/span>\n}<\/span>)<\/span>\n\nfunc<\/span>(<\/span>1<\/span>,<\/span> 2<\/span>,<\/span> 3<\/span>,<\/span> 4<\/span>,<\/span> 5<\/span>)<\/span><\/pre>\n<\/div>\n
\u6211\u4eec\u6765\u5199\u4e00\u7248\uff1a<\/p>\n
<\/p>\n
\/\/ \u7b2c\u4e00\u7248<\/span>\nfunction<\/span> restArgs<\/span>(<\/span>func<\/span>)<\/span> {<\/span>\n    return<\/span> function<\/span>(<\/span>)<\/span>{<\/span>\n        \/\/ startIndex \u8868\u793a\u4f7f\u7528\u54ea\u4e2a\u4f4d\u7f6e\u7684\u53c2\u6570\u7528\u4e8e\u50a8\u5b58\u5269\u4f59\u7684\u53c2\u6570<\/span>\n        var<\/span> startIndex<\/span> =<\/span> func<\/span>.<\/span>length<\/span> -<\/span> 1<\/span>;<\/span>\n        var<\/span> length<\/span> =<\/span> arguments<\/span>.<\/span>length<\/span> -<\/span> startIndex<\/span>;<\/span>\n\n        var<\/span> rest<\/span> =<\/span> Array<\/span>(<\/span>length<\/span>)<\/span>\n        var<\/span> index<\/span> =<\/span> 0<\/span>;<\/span>\n\n        \/\/ \u4f7f\u7528\u4e00\u4e2a\u6570\u7ec4\u50a8\u5b58\u5269\u4f59\u7684\u53c2\u6570<\/span>\n        \/\/ \u4ee5\u4e0a\u9762\u7684\u4f8b\u5b50\u4e3a\u4f8b\uff0c\u7ed3\u679c\u4e3a\uff1a<\/span>\n        \/\/ rest [3, 4, 5]<\/span>\n        for<\/span> (<\/span>;<\/span> index<\/span> <<\/span> length<\/span>;<\/span> index<\/span>++<\/span>)<\/span> {<\/span>\n            rest<\/span>[<\/span>index<\/span>]<\/span> =<\/span> arguments<\/span>[<\/span>index<\/span> +<\/span> startIndex<\/span>]<\/span>\n        }<\/span>\n\n        \/\/ args [1, 2, undefined]<\/span>\n        var<\/span> args<\/span> =<\/span> Array<\/span>(<\/span>startIndex<\/span> +<\/span> 1<\/span>)<\/span>;<\/span>\n        for<\/span> (<\/span>index<\/span> =<\/span> 0<\/span>;<\/span> index<\/span> <<\/span> startIndex<\/span>;<\/span> index<\/span>++<\/span>)<\/span> {<\/span>\n            args<\/span>[<\/span>index<\/span>]<\/span> =<\/span> arguments<\/span>[<\/span>index<\/span>]<\/span>\n        }<\/span>\n\n        \/\/ args [1, 2, [3, 4, 5]]<\/span>\n        args<\/span>[<\/span>startIndex<\/span>]<\/span> =<\/span> rest<\/span>;<\/span>\n\n        return<\/span> func<\/span>.<\/span>apply<\/span>(<\/span>this<\/span>,<\/span> args<\/span>)<\/span>\n    }<\/span>\n}<\/span><\/pre>\n<\/div>\n
\u4f18\u5316<\/h2>\n
\u6211\u4eec\u9ed8\u8ba4\u4f7f\u7528\u4f20\u5165\u7684\u51fd\u6570\u7684\u6700\u540e\u4e00\u4e2a\u53c2\u6570\u50a8\u5b58\u5269\u4f59\u7684\u53c2\u6570\uff0c\u4e3a\u4e86\u66f4\u52a0\u7075\u6d3b\uff0c\u6211\u4eec\u53ef\u4ee5\u518d\u589e\u52a0\u4e00\u4e2a\u53c2\u6570\uff0c\u7528\u6765\u6307\u5b9a startIndex\uff0c\u5982\u679c\u6ca1\u6709\u6307\u5b9a\uff0c\u5c31\u9ed8\u8ba4\u4f7f\u7528\u6700\u540e\u4e00\u4e2a\u53c2\u6570\u3002<\/p>\n
\u6b64\u5916\uff0c\u6ce8\u610f\uff0c\u6211\u4eec\u4f7f\u7528 Array(length) \u521b\u5efa\u6570\u7ec4\uff0c\u800c length \u7684\u8ba1\u7b97\u65b9\u5f0f\u662f arguments.length – startIndex\uff0c\u8fd9\u4e2a\u503c\u6709\u53ef\u80fd\u662f\u8d1f\u6570\uff01\u6bd4\u5982\uff1a<\/p>\n
<\/p>\n
var<\/span> func<\/span> =<\/span> restArgs<\/span>(<\/span>function<\/span>(<\/span>a<\/span>,<\/span> b<\/span>,<\/span> c<\/span>,<\/span> d<\/span>)<\/span>{<\/span>\n    console<\/span>.<\/span>log<\/span>(<\/span>c<\/span>)<\/span> \/\/ \u62a5\u9519<\/span>\n}<\/span>)<\/span>\n\nfunc<\/span>(<\/span>1<\/span>,<\/span> 2<\/span>)<\/span><\/pre>\n<\/div>\n
\u6240\u4ee5\u6211\u4eec\u518d\u5199\u4e00\u7248\uff1a<\/p>\n
<\/p>\n
\/\/ \u7b2c\u4e8c\u7248<\/span>\nfunction<\/span> restArgs<\/span>(<\/span>func<\/span>,<\/span> startIndex<\/span>)<\/span> {<\/span>\n    startIndex<\/span> =<\/span> startIndex<\/span> ==<\/span> null<\/span> ? func<\/span>.<\/span>length<\/span> -<\/span> 1<\/span> : +<\/span>startIndex<\/span>;<\/span>\n    return<\/span> function<\/span>(<\/span>)<\/span>{<\/span>\n        var<\/span> length<\/span> =<\/span> Math<\/span>.<\/span>max<\/span>(<\/span>arguments<\/span>.<\/span>length<\/span> -<\/span> startIndex<\/span>,<\/span> 0<\/span>)<\/span>;<\/span>\n        var<\/span> rest<\/span> =<\/span> Array<\/span>(<\/span>length<\/span>)<\/span>\n        var<\/span> index<\/span> =<\/span> 0<\/span>;<\/span>\n        for<\/span> (<\/span>;<\/span> index<\/span> <<\/span> length<\/span>;<\/span> index<\/span>++<\/span>)<\/span> {<\/span>\n            rest<\/span>[<\/span>index<\/span>]<\/span> =<\/span> arguments<\/span>[<\/span>index<\/span> +<\/span> startIndex<\/span>]<\/span>\n        }<\/span>\n\n        var<\/span> args<\/span> =<\/span> Array<\/span>(<\/span>startIndex<\/span> +<\/span> 1<\/span>)<\/span>;<\/span>\n        for<\/span> (<\/span>index<\/span> =<\/span> 0<\/span>;<\/span> index<\/span> <<\/span> startIndex<\/span>;<\/span> index<\/span>++<\/span>)<\/span> {<\/span>\n            args<\/span>[<\/span>index<\/span>]<\/span> =<\/span> arguments<\/span>[<\/span>index<\/span>]<\/span>\n        }<\/span>\n\n        args<\/span>[<\/span>startIndex<\/span>]<\/span> =<\/span> rest<\/span>;<\/span>\n        return<\/span> func<\/span>.<\/span>apply<\/span>(<\/span>this<\/span>,<\/span> args<\/span>)<\/span>\n    }<\/span>\n}<\/span><\/pre>\n<\/div>\n
\u6027\u80fd\u4f18\u5316<\/h2>\n
\u5982\u679c\u662f\u6b63\u5e38\u5199\u4e1a\u52a1\uff0c\u53ef\u80fd\u5199\u5230\u8fd9\u91cc\u5c31\u7ed3\u675f\u4e86\uff0c\u7136\u800c underscore \u8003\u8651\u7684\u66f4\u591a\uff0c\u9274\u4e8e call \u7684\u6027\u80fd\u8981\u9ad8\u4e8e apply\uff0c\u6240\u4ee5 underscore \u505a\u4e86\u4e00\u4e2a\u4f18\u5316\uff1a<\/p>\n
<\/p>\n
\/\/ \u7b2c\u4e09\u7248<\/span>\nvar<\/span> restArgs<\/span> =<\/span> function<\/span>(<\/span>func<\/span>,<\/span> startIndex<\/span>)<\/span> {<\/span>\n    startIndex<\/span> =<\/span> startIndex<\/span> ==<\/span> null<\/span> ? func<\/span>.<\/span>length<\/span> -<\/span> 1<\/span> : +<\/span>startIndex<\/span>;<\/span>\n    return<\/span> function<\/span>(<\/span>)<\/span> {<\/span>\n        var<\/span> length<\/span> =<\/span> Math<\/span>.<\/span>max<\/span>(<\/span>arguments<\/span>.<\/span>length<\/span> -<\/span> startIndex<\/span>,<\/span> 0<\/span>)<\/span>,<\/span>\n            rest<\/span> =<\/span> Array<\/span>(<\/span>length<\/span>)<\/span>,<\/span>\n            index<\/span> =<\/span> 0<\/span>;<\/span>\n\n        for<\/span> (<\/span>;<\/span> index<\/span> <<\/span> length<\/span>;<\/span> index<\/span>++<\/span>)<\/span> {<\/span>\n            rest<\/span>[<\/span>index<\/span>]<\/span> =<\/span> arguments<\/span>[<\/span>index<\/span> +<\/span> startIndex<\/span>]<\/span>;<\/span>\n        }<\/span>\n\n        \/\/ \u589e\u52a0\u7684\u90e8\u5206<\/span>\n        switch<\/span> (<\/span>startIndex<\/span>)<\/span> {<\/span>\n            case<\/span> 0<\/span>:\n                return<\/span> func<\/span>.<\/span>call<\/span>(<\/span>this<\/span>,<\/span> rest<\/span>)<\/span>;<\/span>\n            case<\/span> 1<\/span>:\n                return<\/span> func<\/span>.<\/span>call<\/span>(<\/span>this<\/span>,<\/span> arguments<\/span>[<\/span>0<\/span>]<\/span>,<\/span> rest<\/span>)<\/span>;<\/span>\n            case<\/span> 2<\/span>:\n                return<\/span> func<\/span>.<\/span>call<\/span>(<\/span>this<\/span>,<\/span> arguments<\/span>[<\/span>0<\/span>]<\/span>,<\/span> arguments<\/span>[<\/span>1<\/span>]<\/span>,<\/span> rest<\/span>)<\/span>;<\/span>\n        }<\/span>\n\n        var<\/span> args<\/span> =<\/span> Array<\/span>(<\/span>startIndex<\/span> +<\/span> 1<\/span>)<\/span>;<\/span>\n        for<\/span> (<\/span>index<\/span> =<\/span> 0<\/span>;<\/span> index<\/span> <<\/span> startIndex<\/span>;<\/span> index<\/span>++<\/span>)<\/span> {<\/span>\n            args<\/span>[<\/span>index<\/span>]<\/span> =<\/span> arguments<\/span>[<\/span>index<\/span>]<\/span>;<\/span>\n        }<\/span>\n\n        args<\/span>[<\/span>startIndex<\/span>]<\/span> =<\/span> rest<\/span>;<\/span>\n        return<\/span> func<\/span>.<\/span>apply<\/span>(<\/span>this<\/span>,<\/span> args<\/span>)<\/span>;<\/span>\n    }<\/span>;<\/span>\n}<\/span>;<\/span><\/pre>\n<\/div>\n
\u81f3\u6b64\uff0crestArgs \u51fd\u6570\u5c31\u5b8c\u6210\u4e86\uff0cunderscore \u5f88\u591a\u51fd\u6570\u6bd4\u5982 invoke\u3001without\u3001union\u3001difference\u3001bind\u3001partial\u3001bindAll\u3001delay \u90fd\u7528\u5230\u4e86 restArgs \u51fd\u6570\u3002<\/p>\n
\u5f53\u4f7f\u7528 underscore \u7684\u65f6\u5019\uff0c\u6211\u4eec\u53ef\u4ee5\u4ee5 _.restArgs \u7684\u5f62\u5f0f\u8c03\u7528\u8be5\u51fd\u6570\u3002<\/p>\n
restArgs \u4e0e partial<\/h2>\n
\u6700\u540e\uff0c\u4f7f\u7528\u6211\u4eec\u7684\u5199\u7684 restArgs \u51fd\u6570\u91cd\u5199\u4e0b partial \u51fd\u6570\uff1a<\/p>\n
<\/p>\n
var<\/span> partial<\/span> =<\/span> restArgs<\/span>(<\/span>function<\/span>(<\/span>fn<\/span>,<\/span> args<\/span>)<\/span>{<\/span>\n    return<\/span> restArgs<\/span>(<\/span>function<\/span>(<\/span>partialArgs<\/span>)<\/span> {<\/span>\n        var<\/span> newArgs<\/span> =<\/span> args<\/span>.<\/span>concat<\/span>(<\/span>partialArgs<\/span>)<\/span>;<\/span>\n        return<\/span> fn<\/span>.<\/span>apply<\/span>(<\/span>this<\/span>,<\/span> newArgs<\/span>)<\/span>;<\/span>\n    }<\/span>)<\/span>\n}<\/span>)<\/span>\n\nfunction<\/span> add<\/span>(<\/span>a<\/span>,<\/span> b<\/span>,<\/span> c<\/span>)<\/span> {<\/span>\n    return<\/span> a<\/span> +<\/span> b<\/span> +<\/span> c<\/span>;<\/span>\n}<\/span>\n\nvar<\/span> addOne<\/span> =<\/span> partial<\/span>(<\/span>add<\/span>,<\/span> 1<\/span>)<\/span>;<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>addOne<\/span>(<\/span>2<\/span>,<\/span> 3<\/span>)<\/span>)<\/span>;<\/span> \/\/ 6<\/span><\/pre>\n<\/div>\n
underscore \u7cfb\u5217<\/h2>\n
underscore \u7cfb\u5217\u76ee\u5f55\u5730\u5740\uff1ahttps:\/\/github.com\/mqyqingfeng\/Blog<\/a>\u3002<\/p>\n
underscore \u7cfb\u5217\u9884\u8ba1\u5199\u516b\u7bc7\u5de6\u53f3\uff0c\u91cd\u70b9\u4ecb\u7ecd underscore \u4e2d\u7684\u4ee3\u7801\u67b6\u6784\u3001\u94fe\u5f0f\u8c03\u7528\u3001\u5185\u90e8\u51fd\u6570\u3001\u6a21\u677f\u5f15\u64ce\u7b49\u5185\u5bb9\uff0c\u65e8\u5728\u5e2e\u52a9\u5927\u5bb6\u9605\u8bfb\u6e90\u7801\uff0c\u4ee5\u53ca\u5199\u51fa\u81ea\u5df1\u7684 undercore\u3002<\/p>\n<\/td>\n
\u6587\u7ae0\u8f6c\u8f7d\u81eahttps:\/\/github.com\/mqyqingfeng\/Blog\/issues\/60<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"
partial \u5728\u300a JavaScript \u4e13\u9898\u4e4b\u504f\u51fd\u6570\u300b\u4e2d\uff0c\u6211\u4eec\u5199\u4e86\u4e00\u4e2a partial \u51fd\u6570\uff0c\u7528\u6765\u56fa\u5b9a\u51fd\u6570\u7684\u90e8\u5206\u53c2\u6570\uff0c\u5b9e\u73b0\u4ee3\u7801\u5982\u4e0b\uff1a \/\/ \u8fd9\u662f\u6587\u7ae0\u4e2d\u7684\u7b2c\u4e00…<\/p>\n
 Read More  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-1368","post","type-post","status-publish","format-standard","hentry","category-learn"],"_links":{"self":[{"href":"https:\/\/www.lccc.top\/index.php?rest_route=\/wp\/v2\/posts\/1368"}],"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=1368"}],"version-history":[{"count":1,"href":"https:\/\/www.lccc.top\/index.php?rest_route=\/wp\/v2\/posts\/1368\/revisions"}],"predecessor-version":[{"id":1473,"href":"https:\/\/www.lccc.top\/index.php?rest_route=\/wp\/v2\/posts\/1368\/revisions\/1473"}],"wp:attachment":[{"href":"https:\/\/www.lccc.top\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1368"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.lccc.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1368"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.lccc.top\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1368"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}