javascript bind binding function code_javascript skills

For specific conclusions, please refer to "Dynamic this and dynamic binding example code under javascript". This article focuses on designing a non-intrusive binding function.

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Based on not extending native objects In principle, I created this bind function (dom is the scope), and its usage is similar to the bind of the Prototype framework.

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The code is as follows:

dom.bind = function(fn,context){
//If you like, the second parameter can also be changed to thisObject, scope,
//In short, it is a new scope object
if (arguments.length < 2 && context== =undefined) return fn;
var method = fn,
slice = Array.prototype.slice,
args = slice.call(arguments, 2);
return function(){//here Pass in the parameters of the original fn
var array = slice.call(arguments, 0);
method.apply(context,args.concat(array))
}

Usage: The first parameter is the function that needs to be bound to the scope, the second is the window or various objects, and other parameters are optional.

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Another example:

[Ctrl A select all Note: <script> window.name = "the window object" function scopeTest() { return this.name } // calling the function in global scope: scopeTest() // -> "the window object" var foo = { name: "the foo object!", otherScopeTest: function() { return this.name } } foo.otherScopeTest() // -> "the foo object!" </script>If you need to introduce external Js, you need to refresh to execute <script> dom = {}; dom.bind = function(fn,context){ if (arguments.length < 2 && context===undefined) return fn; var method = fn, slice = Array.prototype.slice, args = slice.call(arguments, 2); return function(){//这里传入原fn的参数 var array = slice.call(arguments, 0); method.apply(context,args.concat(array)) } } window.name = 'This is window'; var jj = { name: '这是jj', alertName: function() {//绑定失效 alert(this.name); } }; var kk = { name:"kkです" } function run(f) { f(); } run(jj.alertName); var fx2 = dom.bind(jj.alertName,jj) run(fx2); var fx3 = dom.bind(jj.alertName,window) run(fx3); var fx4 = dom.bind(jj.alertName,kk) run(fx4); </script>]<script> dom = {}; dom.bind = function(fn,context){ if (arguments.length < 2 && context===undefined) return fn; var method = fn, slice = Array.prototype.slice, args = slice.call(arguments, 2); return function(){//这里传入原fn的参数 var array = slice.call(arguments, 0); method.apply(context,args.concat(array)) } } var obj = { name: 'A nice demo', fx: function() { alert(this.name + '\n' + Array.prototype.slice.call(arguments,0).join(', ')); } }; var fx2 = dom.bind(obj.fx,obj, 1, 2, 3); fx2(4, 5); // Alerts the proper name, then "1, 2, 3, 4, 5" </script>