blocks|key|3657750|text|调用makeAdder(5)时，它将返回对新函数的引用。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|3657751|function(y)+{
++++return+x+%2B+y;
};|code-block|syntax|javascript|3657752|所以add5保留了引用。在调用add5(2)之后，将2传递给函数。在它中，当它想返回x+%2B+y时，它开始查找变量。从x开始，它查找并看到没有在其中定义x，然后转到定义内部函数的scope在这里|3657753|function+makeAdder(x)+{
++return+function(y)+{
++++return+x+%2B+y;
++};
}|3657754|它在这里定义了x，因为您在var+add5+=+makeAdder(5);期间调用并传递了x。在找到y并在它的作用域中找到之后。最后返回x+%2B+y。|3657755|的思想是，每个函数都有对它的创建者的引用(定义它的地方)，当它找不到变量时，它会在其中找到更大的变量，直到全局范围。|BOLD|3657756|entityMap^0|2|C|0|0|2|4|F|7|Q|1|16|5|1M|1|23|1|2G|5|0|0|7|1|H|K|19|1|1E|1|1W|5|0|0|1M|0^^$0|@$1|2|3|4|5|6|7|V|8|@$9|W|A|X|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|Y|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|Z|8|@$9|10|A|11|B|C]|$9|12|A|13|B|C]|$9|14|A|15|B|C]|$9|16|A|17|B|C]|$9|18|A|19|B|C]|$9|1A|A|1B|B|C]|$9|1C|A|1D|B|C]]|D|@]|E|$]]|$1|M|3|N|5|H|7|1E|8|@]|D|@]|E|$I|J]]|$1|O|3|P|5|6|7|1F|8|@$9|1G|A|1H|B|C]|$9|1I|A|1J|B|C]|$9|1K|A|1L|B|C]|$9|1M|A|1N|B|C]|$9|1O|A|1P|B|C]]|D|@]|E|$]]|$1|Q|3|R|5|6|7|1Q|8|@$9|1R|A|1S|B|S]]|D|@]|E|$]]|$1|T|3|-4|5|6|7|1T|8|@]|D|@]|E|$]]]|U|$]]

When you call your <code>makeAdder(5)</code>, it returns the reference to a new function.

<pre><code>function(y) {
 return x + y;
};
</code></pre>

So <code>add5</code> keeps the reference. After it when you call <code>add5(2)</code>, you pass the <code>2</code> to the function. In it when it wants to return <code>x + y</code>, it starts to find the variables. Starting from <code>x</code>, it looks and see's that the <code>x</code> is not defined in it and goes to the <code>scope</code> in which inner function was defined ` here 

<pre><code>function makeAdder(x) {
 return function(y) {
 return x + y;
 };
}
</code></pre>

It see's than <code>x</code> was defined here, because you call and pass <code>x</code> during var <code>add5 = makeAdder(5);</code>. After it goes to find <code>y</code> and finds in it's scope. And after all returns <code>x + y</code>.

The idea is this, every function has a reference to it's creater (where it was defined) and when it doesn't find a variable, it goes to find in it's greater and so till to global scope.

blocks|key|3657758|text|function+makeAdder(x)+{
++return+function(y)+{
++++return+x+%2B+y;
++};
}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|3657759|当您执行var+add5+=+makeAdder(5);时，add5变成了一个返回我的makeAdder的函数，add5将如下所示|unstyled|offset|length|style|CODE|3657760|function(y){
+++return+5+%2B+y;
}|3657761|所以当你做add5(2)时，它会做5%2B2，然后返回7；|3657762|entityMap^0|0|4|O|U|4|17|9|1K|4|0|0|5|7|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|R|8|@$G|S|H|T|I|J]|$G|U|H|V|I|J]|$G|W|H|X|I|J]|$G|Y|H|Z|I|J]]|9|@]|A|$]]|$1|K|3|L|5|6|7|10|8|@]|9|@]|A|$B|C]]|$1|M|3|N|5|F|7|11|8|@$G|12|H|13|I|J]]|9|@]|A|$]]|$1|O|3|-4|5|F|7|14|8|@]|9|@]|A|$]]]|P|$]]

<pre><code>function makeAdder(x) {
 return function(y) {
 return x + y;
 };
}
</code></pre>

When you do <code>var add5 = makeAdder(5);</code> the <code>add5</code> becomes a function which was returnd my <code>makeAdder</code>,
the <code>add5</code> will be following

<pre><code>function(y){
 return 5 + y;
}
</code></pre>

so when you do <code>add5(2)</code> it will do 5 + 2 and will return 7;

blocks|key|1283590|text|makeAdder(5)+|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1283591|X+=>+5和y没有值，所以x%2By+=>+5%2B0+=>+5|unstyled|1283592|var+add5+=+makeAdder(5);
add5(2);|1283593|我们已经用x+=>+5为函数makeadder创建了变量，所以现在我们传递y+=>+2和x+=>+5，所以x%2By+=>+5%2B2+=>+7。|1283594|外部函数变量在内部函数中可访问的这个属性在javascript中称为闭包属性。此外，对y变量的添加对于外部函数也是不可访问的。|1283595|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|P|8|@]|9|@]|A|$]]|$1|G|3|H|5|6|7|Q|8|@]|9|@]|A|$B|C]]|$1|I|3|J|5|F|7|R|8|@]|9|@]|A|$]]|$1|K|3|L|5|F|7|S|8|@]|9|@]|A|$]]|$1|M|3|-4|5|F|7|T|8|@]|9|@]|A|$]]]|N|$]]

<pre><code>makeAdder(5) 
</code></pre>

x => 5 and y is not having value so x+y => 5+0 => 5

<pre><code>var add5 = makeAdder(5);
add5(2);
</code></pre>

we have created variable for the function makeadder with x => 5
so now we pass y => 2 and x => 5 so x+y => 5+2 => 7

This property of outer function variable accessible in inner function is called closure property in javascript. Also adding to that y variable is not accessible to outer function.

Can anyone explain how this code works?

<pre><code>function makeAdder(x) {
 return function(y) {
 return x + y;
 };
}

var add5 = makeAdder(5);
var add10 = makeAdder(10);

console.log(add5(2)); // 7
console.log(add10(2)); // 12
</code></pre>

Reference: <a href="https://mozilla.org/en/docs/Web/JavaScript/Closures" rel="nofollow noreferrer">https://mozilla.org/en/docs/Web/JavaScript/Closures</a>

JavaScript Closures - Program flow

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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有人能解释一下这段代码是如何工作的吗？function makeAdder(x) {  return function(y) {    return x + y;  };}var add5 = makeAdder(5);var add10 = makeAdder(10);console.log(add5(2));  /...

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