JavaScript this.window不等于window [英] JavaScript this.window not equal to window

问题描述

考虑以下顶级JavaScript代码：

Consider the following top-level javascript code:

if (this.window === window)
    alert('same');
else
    alert('different'); // alerts: different  

为什么this.window和窗口不严格相等？我还在表达式的rhs上尝试了'this'并得到了相同的结果。

Why is this.window and window not strictly equal? I've also tried 'this' on the rhs of the expression and get the same result.

推荐答案

在Internet Explorer中（8.0） .7600是我测试的），这个没有限定符实际上解析为全局窗口对象。在我尝试过的所有其他浏览器中（Chrome，Firefox，Opera）， this.window === window 在该上下文中 - 并且，有用的是，这个===窗口以及。

In Internet Explorer (8.0.7600 is what I've tested), this with no qualifier actually resolves to the global window object. In all other browsers I've tried (Chrome, Firefox, Opera), this.window === window in that context - and, helpfully, this === window as well.

在IE中尝试验证：

if (this === window)
  alert('same');
else
  alert('different');

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