Question

Closed 11 years ago.

与其它语言不同,在JavaScript this 中,总是指我们执行的函数的“所有人”,或是指函数是一种方法的对象。

这种行为的优势/目的与其他语言拼凑在一起有哪些?

Answer 1

既然您被允许设置此选项, 您可以设置您调用的任何函数的范围, 允许您在功能关闭时做一些有趣的事情。这就是大多数 JS 框架允许您做更多自然对象导向类行为的方式。当您有活动听众并且想要设置监听功能的范围时, 这特别有用。

Answer 2

By default, this refers to the global object.
When a function is called as a property on a parent object, this refers to the parent object inside that function.
When a function is called with the new operator, this refers to the newly created object inside that function.
When a function is called using call or apply, this refers to the first argument passed to call or apply. If the first argument is null or not an object, this refers to the global object.

也调查一下这个