这在全球范围内 [英] this in a global scope

问题描述

声明：

for( var item in this){
    console.log( item );
}

在全局范围内是否为noop。但是在函数中

Is a noop in the global context. However in a function

function foo(){
    for( var item in this){
        console.log( item );
    }
}
foo();

这将生成全局环境对象。
这种行为的原因是什么？

This produces the global environment objects. What is the reason for this behaviour?

访问当前范围内的对象的语法是什么，如第一个样本？

What is the syntax for accessing the objects currently in scope, as in the first sample?

推荐答案

此可能指向节点的exports对象。

The this is probably pointing to the exports object of node.

所以在第一种情况下，这个是不是指向窗口这个在一个函数内（它不是一个对象的方法）所以，正如你所期望的那样，它指向 window 。

So in the first case, the this is right not to point at the window object. In the second case, well, the this is inside a function (which is not a method of an object) so, as you'd expect, it points back to the window.

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