解释John Resig的一些忍者代码 [英] Explaining some of John Resig's ninja code

问题描述

Function.prototype.bind = function(){
     var fn = this, args = Array.prototype.slice.call(arguments),
      object = args.shift();
      return function(){
              return fn.apply(object,
                   args.concat(Array.prototype.slice.call(arguments)));
      };
};


var myObject = {};
function myFunction(){
    return this == myObject;
}
assert( !myFunction(), "Context is not set yet" );
var aFunction = myFunction.bind(myObject)
assert( aFunction(), "Context is set properly" );

下面对Jeffery代码的微小修改帮助我理解了内部匿名函数中使用的参数。我只是更改了下面的3行

Tiny modification to Jeffery's code below helped me understand the arguments used in the inner anonymous function. I just changed the 3 lines below

var introduce = function(greeting) { alert(greeting + ", my name is " + this.name + " ,home no is " + arguments[1]); }

hiBob(" 456"); // alerts "Hi, my name is Bob"
yoJoe(" 876");  

谢谢大家

推荐答案

参数对象是一个类似数组的对象，它只有length属性。

The arguments object is an array-like object, it has only the length property.

通过Array.prototype调用slice函数是将它转换为数组的常用技术，因此您将能够使用数组函数，如 shift 和 concat ，直接。

Calling the slice function through the Array.prototype is a common technique to convert it to an array, so you will be able to use array functions like shift and concat on this example, directly.

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