var $ this = this的原因是什么？

本文介绍了var $ this = this的原因是什么？的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我不是最好的jquery，我遇到了一个var初始化，我不知道编写代码的人为什么会这样做。

I'm not the best at jquery and I came across a var initialization that I don't know why the person who wrote the code did it this way.

在插件的init中，我们有

In the init for a plugin, we have

this.init = function(settings) { var $this = this; this.s = { initialSlide: 0, firstSlide: true, }; ... more code, some uses $this, some uses "this" }

那么$ this和this之间有什么区别？为什么不一直使用一个或另一个？

So what is the difference here between "$this" and "this" and why not use one or the other all the time?

推荐答案

通常，这意味着此的副本。关于这个的事情是它在每个函数中都会发生变化。但是，以这种方式存储会使 $ this 保持不变，而此确实会发生变化。

Generally, this means a copy of this. The thing about this is that it changes within each function. Storing it this way, however, keeps $this from changing whereas this does change.

jQuery大量使用魔法这个值。

jQuery heavily uses the magic this value.

考虑这段代码，你在哪里可能需要你看到的东西：

Consider this code, where you might need something like you are seeing:

$.fn.doSomethingWithElements = function() { var $this = this; this.each(function() { // `this` refers to each element and differs each time this function // is called // // `$this` refers to old `this`, i.e. the set of elements, and will be // the same each time this function is called }); };