{"id":228,"date":"2021-04-09T21:58:19","date_gmt":"2021-04-09T13:58:19","guid":{"rendered":"http:\/\/gjweb.top\/?p=228"},"modified":"2021-04-09T21:58:20","modified_gmt":"2021-04-09T13:58:20","slug":"%e5%87%bd%e6%95%b0%e7%9a%84%e7%8e%af%e5%a2%83","status":"publish","type":"post","link":"https:\/\/gjweb.top\/?p=228","title":{"rendered":"\u51fd\u6570\u7684\u73af\u5883"},"content":{"rendered":"\n<h3 class=\"wp-block-heading\">\u51fd\u6570VS\u65b9\u6cd5\u7684\u533a\u522b<\/h3>\n\n\n\n<ul class=\"wp-block-list\"><li>\u51fd\u6570<\/li><li>\u5982\u679c\u5b50\u7a0b\u5e8f\u6709\u8fd4\u56de\u503c,\u5c31\u4e00\u4e2a\u51fd\u6570(js\u7684\u6240\u6709\u51fd\u6570\u90fd\u6709\u8fd4\u56de\u503c);\u5982\u679c\u51fd\u6570\u91cc\u9762\u6ca1\u5199return,js\u4f1a\u81ea\u52a8\u52a0\u4e0areturn.<ul><li>\u4ec0\u4e48\u662f\u5b50\u7a0b\u5e8f<\/li><li>\u4e00\u4e2a\u6216\u591a\u4e2a\u8bed\u53e5\u7ec4\u6210\u5b8c\u6210\u7279\u5b9a\u529f\u80fd\u4e14\u76f8\u5bf9\u72ec\u7acb\u7684\u79f0\u4e3a\u5b50\u7a0b\u5e8f<\/li><\/ul><\/li><li>\u65b9\u6cd5<\/li><li>\u7b80\u5355\u6765\u8bf4\u653e\u5728\u7c7b\u6216\u8005\u5bf9\u8c61\u4e2d\u8c03\u7528\u7684\u51fd\u6570,\u6210\u4e3a\u65b9\u6cd5 (\u65b9\u6cd5\u662f\u6bd4\u8f83\u7279\u6b8a\u7684\u51fd\u6570)<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>\/**\u51fd\u6570**\/\nfunction fun1(num){\n    console.log(num)\n    var num = num + 2\n    return num\n}\nfun1(2)\n\/**\u65b9\u6cd5**\/\nvar obj = {\n    name:'hello',\n    age:18,\n    fun:function(){\n        console.log(this.name)\n    }\n}\n\/\/ OR\nvar abc = function(){\n    ...\n}<\/code><\/pre>\n\n\n\n<h2 class=\"wp-block-heading\">\u51fd\u6570\u7684\u8fd4\u56de\u503c\u7531\u4ec0\u4e48\u786e\u5b9a<\/h2>\n\n\n\n<ul class=\"wp-block-list\"><li>\u4e00\u4e2a\u51fd\u6570\u7684\u8fd4\u56de\u65f6\u503c\u662f\u7531 \u8c03\u7528\u65f6\u7684\u53c2\u6570\u548c\u5b9a\u4e49\u65f6\u7684\u73af\u5883\u51b3\u5b9a\u7684<\/li><li>\u8c03\u7528\u65f6\u8f93\u5165\u7684\u53c2\u6570 params<\/li><li>\u5b9a\u4e49\u65f6\u7684\u73af\u5883 env<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>let x = \"x\"\nlet a = \"1\"\nfunction f1(x){ \n    return x+a\n}\n{\n    let a = 2;\n    f1('x') \/\/ \u503c\u4e3a x1\n}<\/code><\/pre>\n\n\n\n<p>\u4e0a\u8ff0\u4ee3\u7801\u4e2d x \u662f\u53c2\u6570, a\u5c31\u662f\u73af\u5883<\/p>\n\n\n\n<hr class=\"wp-block-separator\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">js\u95ed\u5305<\/h2>\n\n\n\n<p>\u200b \u5982\u679c\u5728\u51fd\u6570\u91cc\u9762\u53ef\u4ee5\u8bbf\u95ee\u5916\u9762\u51fd\u6570\u7684\u53d8\u91cf,\u90a3\u4e48\u8fd9\u4e2a\u51fd\u6570+\u8fd9\u4e9b\u53d8\u91cf = \u95ed\u5305<\/p>\n\n\n\n<p>\u5982\u4f55\u7528\u95ed\u5305\u9690\u85cf\u4e00\u4e2a\u53d8\u91cf\u7684\u64cd\u4f5c?<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">\u6269\u5c55<\/h3>\n\n\n\n<p>\u7528\u5bf9\u8c61\u6a21\u62df\u95ed\u5305<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>let obj = {\n    _i:0,\n    fn(){\n        console.log(this._i)\n    }\n}<\/code><\/pre>\n\n\n\n<p>\u95ed\u5305\u6a21\u62df\u5bf9\u8c61<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>function createPerson(age,name){\n    return function(key){\n        if(key === 'name') return name;\n        if(key === \"age\") return age;\n    }\n}\nvar person = createPerson('18','xiaoming');\nperson('name'); \/\/ xiaoming\nperson('age'); \/\/ 18<\/code><\/pre>\n\n\n\n<hr class=\"wp-block-separator\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">this\u7684\u503c<\/h2>\n\n\n\n<p>\u51fd\u6570\u8fd4\u56de\u503c\u7684\u5f71\u54cd\u56e0\u7d20<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>\u8c03\u7528\u65f6\u8f93\u5165\u7684\u53c2\u6570 params<\/li><li>\u666e\u901a\u51fd\u6570\u7684 this \u5728\u53c2\u6570\u4e2d<\/li><li>\u5b9a\u4e49\u65f6\u7684\u73af\u5883 env<\/li><li>\u7bad\u5934\u51fd\u6570\u7684 this \u5728\u73af\u5883\u4e2d<\/li><\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">this\u7684\u9690\u5f0f\u8f6c\u6362<\/h2>\n\n\n\n<pre class=\"wp-block-code\"><code>fn(1,2)\n\/\/ fn.call(undefined,1,2) \/\/ window\nobj.method(\"h1\")\n\/\/ obj.method.call(obj.'h1')\narray&#91;0](\"hi\")\n\/\/ array&#91;0].call(array,'hi')<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\">\u6d4b\u8bd5\u4e00<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>button.onclick = function(e){\n    console.log(this)\n}\n\/\/ \u7528\u6237\u70b9\u51fb\u7684\u65f6\u5019 this \u662f button\n\nlet fn = button.onclick();\nfn()\n\/\/ \u8fd9\u4e2a\u65f6\u5019 this \u6307\u5411\u7684\u662f window\nfn.call({name:'hell'})\nfn()\n\/\/ \u8fd9\u4e2a\u65f6\u5019 this \u6307\u5411\u7684call\\bind\\apply \u7684\u7b2c\u4e00\u4e2a\u53c2\u6570<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\">\u6d4b\u8bd5\u4e8c<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>let length = 10;\nfunction fn(){console.log(this.length)}\nlet obj = {\n    length:5,\n    method(fn){\n        fn()\n        arguments&#91;0]()\n    }\n}\nobj.method(fn,1)<\/code><\/pre>\n\n\n\n<h4 class=\"wp-block-heading\">\u5206\u6790\u4e00<\/h4>\n\n\n\n<pre class=\"wp-block-code\"><code>let length = 10; \nfunction fn(){console.log(this.length)} \nlet obj = {\n    length:5,\n    method(fn){\n        \/\/ fn()\n        \/\/ \u53ef\u4ee5\u7406\u89e3\u6210\n        fn.call(undefined) \/\/ \u8fd9\u65f6\u7684this\u6307\u5411window,\u4f46\u662flet\u58f0\u660e\u7684\u53d8\u91cf\u4e0d\u4f1a\u6302\u5230window;\n        \/\/ \u8fd0\u884c\u7a0b\u5e8f\u6253\u5370\u7684length\u8bfb\u53d6\u7684\u662f\u5f53\u524d\u9875\u9762\u6709\u591a\u5c11\u4e2a\u7a97\u53e3(iframe)\n    }\n}\nobj.method(fn,1)<\/code><\/pre>\n\n\n\n<h4 class=\"wp-block-heading\">\u5206\u6790\u4e8c<\/h4>\n\n\n\n<p>\u5206\u6790arguments\u7684this<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>let length = 10;\nfunction fn(){console.log(this.length)} \/\/2\nlet obj = {\n    length:5,\n    method(fn){\n        \/\/ arguments&#91;0]()\n        arguments.0.call(arguments) \/\/\u8fd9\u91cc\u7684arguments\u6307\u4ee3\u7684\u662fobj.method\u7684\u5f62\u53c2\u957f\u5ea6\n    }\n}\nobj.method(fn,1)<\/code><\/pre>\n\n\n\n<hr class=\"wp-block-separator\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">\u9012\u5f52\u4e0e\u8fed\u4ee3<\/h2>\n\n\n\n<p>\u9012\u5f52<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>j = (n)=&gt; n===1?1:n*j(n-1)\n\/**\u4ee3\u5165\u6cd5*\/\nj(4)\n= 4* j(3)\n= 4* (3*j(2))\n= 4* (3*j(2*j(1)))\n= 4* (3*2)\n= 4* 6\n= 24<\/code><\/pre>\n\n\n\n<p>\u4f7f\u7528\u8fed\u4ee3\u4ee3\u66ff\u9012\u5f52(\u5c3e\u9012\u5f52)<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>f=(n) =&gt; f_inner(2,n,1,0)\nf_inner = (start,end,prev1,prev2)=&gt;{\n    return start === end?prev1+prev2:f_inner(start+1,end,prev1+prev2,prev1)\n}<\/code><\/pre>\n\n\n\n<hr class=\"wp-block-separator\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">\u8bb0\u5fc6\u5316\u4e0eReact\u4f18\u5316<\/h2>\n\n\n\n<p>\u8bb0\u5fc6\u5316\u53ef\u4ee5\u51cf\u5c11\u91cd\u590d\u8ba1\u7b97,\u5927\u5927\u964d\u4f4e\u538b\u6808\u6b21\u6570<\/p>\n\n\n\n<hr class=\"wp-block-separator\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">\u67ef\u91cc\u5316 Currying<\/h2>\n\n\n\n<ul class=\"wp-block-list\"><li>\u8ba9\u6240\u6709\u51fd\u6570\u53ea\u63a5\u53d7\u4e00\u4e2a\u53c2\u6570<\/li><li>\u95ee\u9898: \u600e\u4e48\u652f\u6301\u4e24\u4e2a\u53c2\u6570?<\/li><li>\u5229\u7528\u95ed\u5305\u63a5\u6536\u4e24\u4e2a\u53c2\u6570<\/li><li>\u5229\u7528\u5bf9\u8c61<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>\/*\u5229\u7528\u95ed\u5305*\/\nconst add = a =&gt; b=&gt; a+b;\nadd(1)(2)\n\/*\u5229\u7528\u5bf9\u8c61*\/\nconst add = ({a,b})=&gt;{a+b}\nadd({a:1,b:2})<\/code><\/pre>\n\n\n\n<p>\u5982\u4f55\u67ef\u91cc\u5316\u4e00\u4e2a\u51fd\u6570<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>\u628a\u591a\u53c2\u6570\u51fd\u6570\uff0c\u53d8\u6210\u5355\u53c2\u6570\u51fd\u6570<\/li><\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">\u95ee\u9898\uff1a \u5982\u4f55\u628a\u4e09\u53c2\u6570\u51fd\u6570add(1,2,3) \u53d8\u6210 curriedAdd(1)(2)(3)\u7684\u5f62\u5f0f?<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>const cirroedAdd = \n      a=&gt;\n        b=&gt;\n            c=&gt;\n                add(a,b,c)<\/code><\/pre>\n\n\n\n<h4 class=\"wp-block-heading\">\u5347\u7ea7\u7248<\/h4>\n\n\n\n<pre class=\"wp-block-code\"><code>\/*\n    \u5047\u8bbe\n    addTwo \u63a5\u6536\u4e24\u4e2a\u53c2\u6570\n    addThree \u63a5\u6536\u4e09\u4e2a\u53c2\u6570\n    addFore \u63a5\u6536\u56db\u4e2a\u53c2\u6570\n    \u8bf7\u5199\u51fa\u4e00\u4e2a currify \u51fd\u6570,\u4f7f\u5f97\u4ed6\u4eec\u5206\u522b\u63a5\u65362\\3\\4\u6b21\u53c2\u6570\n    \u6bd4\u5982\n        currify(addTwo)(1)(2) \/\/3\n        currify(addThree)(1)(2)(3)\/\/6\n        currify(addFore)(1)(2)(3)(4) \/\/10\n*\/\n\naddTwo = (a,b)=&gt;a+b;\naddThree = (a,b,c)=&gt;a+b+c;\naddFore = (a,b,c,d)=&gt;a+b+c+d;\ncurrify = (fn,params=&#91;])=&gt;{\n    return (arg)=&gt;{\n        const newParams = params.concat(arg);\n        if(newParams.length === fn.length){\n           return fn(...newParams)\n        }else{\n            return currify(fn,newParams)\n        }\n    }\n}\nnewAddTwo = currify(addTwo)\nconsole.log(newAddTwo(1)(2))\nnewAddThree = currify(addThree)\nconsole.log(newAddThree(1)(2)(3))\nnewAddFore = currify(addFore)\nconsole.log(newAddTwo(1)(2)(3)(4))<\/code><\/pre>\n\n\n\n<hr class=\"wp-block-separator\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">\u9ad8\u9636\u51fd\u6570<\/h2>\n\n\n\n<p>\u66f4\u65b0\u4e2d\u3002\u3002\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u51fd\u6570VS\u65b9\u6cd5\u7684\u533a\u522b \u51fd\u6570 \u5982\u679c\u5b50\u7a0b\u5e8f\u6709\u8fd4\u56de\u503c,\u5c31\u4e00\u4e2a\u51fd\u6570(js\u7684\u6240\u6709\u51fd\u6570\u90fd\u6709\u8fd4\u56de\u503c);\u5982\u679c\u51fd\u6570\u91cc\u9762\u6ca1\u5199retu [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[30],"tags":[],"class_list":["post-228","post","type-post","status-publish","format-standard","hentry","category-js"],"_links":{"self":[{"href":"https:\/\/gjweb.top\/index.php?rest_route=\/wp\/v2\/posts\/228","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/gjweb.top\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/gjweb.top\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/gjweb.top\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/gjweb.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=228"}],"version-history":[{"count":0,"href":"https:\/\/gjweb.top\/index.php?rest_route=\/wp\/v2\/posts\/228\/revisions"}],"wp:attachment":[{"href":"https:\/\/gjweb.top\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=228"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/gjweb.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=228"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/gjweb.top\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=228"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}