jquery.each 函数是否有可能不破坏“this"变量? [英] Is it possible for jquery.each function not to clobber the 'this' variable?

问题描述

所以如果变量this"当前设置为一个对象，

So if the variable "this" is currently set to an object,

{ name: "The old this" }

下面的代码会在循环中改变它

the following code will change it in the loop

var array = [1, 2, 3];
$.each(array,
  function(i, e){
    alert(this.name);
  }
);

不会找到this.name，而是在循环执行期间将变量this"设置为与e"相同

this.name wont be found, instead the variable "this" is set to the same as 'e' during the loop execution

jquery 是否可以不破坏 $.each 循环上的 this 变量?

Is it possible to have jquery not clobber the this variable on $.each loops?

推荐答案

如果你使用原生的 .forEach 而不是 $.each，你可以设置 this 通过发送第二个参数的回调值...

If you use the native .forEach instead of $.each, you can set the this value for the callback by sending a second argument...

array.forEach(function(e, i) {
    alert(this.name);
}, this);

您需要修补旧版浏览器，包括 IE8...

You'll need to patch older browsers, including IE8...

• 兼容性补丁来自 MDN

• Compatibility patch from MDN

或者你可以使用 jQuery 的 $.proxy 返回一个具有所需 this 值的函数...

Or you can use jQuery's $.proxy to return a function with the desired this value...

$.each(array, $.proxy(function(i, e) {
    alert(this.name);
}, this) );

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