关于javascript：在Node中，这个内部函数等于undefined


In Node, this inside function equals undefined

本问题已经有最佳答案，请猛点这里访问。

在node中，我怎么会在这个例子中未定义？

因为我没有使用严格模式，所以应该可以从函数内部访问它，并等于全局对象。

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this.foo ="bar";

function fun () {
    console.log(this.foo);
}

fun(); // undefined
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参见MDN中有关"use strict"模式的片段。

First, the value passed as this to a function in strict mode is not forced into being an object (a.k.a."boxed"). For a normal function, this is always an object: either the provided object if called with an object-valued this; the value, boxed, if called with a Boolean, string, or number this; or the global object if called with an undefined or null this... for a strict mode function, the specified this is not boxed into an object, and if unspecified, this will be undefined:

有关最佳解释和示例，请参阅参考："安全"javascript(MDN)

另请参见stackoverflow中的本文：在node.js中，如何解释"use strict"语句？

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