有人可以向我解释这个功能是如何工作的吗?

问题描述：

我正在学习编码，我正在尝试理解高阶函数和抽象.我不明白这段代码如何运行以返回true".

I'm learning to code and I'm trying to understand Higher Order Functions and abstractions. I don't understand how this piece of code runs to return "true".

function greaterThan(n) {
  return function(m) { return m > n; };
}

var greaterThan10 = greaterThan(10);

console.log(greaterThan10(11));

感谢您的帮助.

答

greaterThan 函数在调用时返回一个函数.即使在函数返回之后，返回的函数也可以访问外部函数的所有成员.这称为closure.

The function greaterThan returns a function when called. The returned function has access to all the members of the outer function even after the function has returned. This is called closure.

function greaterThan(n) {
    return function (m) {
        return m > n;
    };
}

执行以下语句时

var greaterThan10 = greaterThan(10);

转换为

var greaterThan10 = function (m) {
    return m > 10;
};

所以，greaterThan10 现在是函数，可以调用为

So, greaterThan10 is now the function and can be called as

console.log(greaterThan10(11));

现在，m 的值为 11 并且 return 11 >10; 返回为 true.

Now, value of m is 11 and return 11 > 10; returns as true.

阅读有关闭包的更多信息:

有人可以向我解释这个功能是如何工作的吗?

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