在jQuery每个循环中获取元素的父元素[复制](Get parent of element in jQuery each loop [duplicate])

在jQuery每个循环中获取元素的父元素[复制](Get parent of element in jQuery each loop [duplicate])

这个问题在这里已经有了答案：

箭头函数与函数声明/表达式：它们是等价的还是可交换的？ 2个答案

我完全沉迷于此。 我在页面上有三个元素，其中有一类.topic-link 。

<div id="parent1"> <a href="#" class="topic-link"></a> </div> <div id="parent2"> <a href="#" class="topic-link"></a> </div> <div id="parent3"> <a href="#" class="topic-link"></a> </div>

我可以运行$('.topic-link').eq(0).parent(); 在JS控制台中并返回正确的父代。 但是当我遍历它们时，每次都会得到一个空对象。

$('.topic-link').each( () => { console.log($(this).parent()); }); // returns 3 empty objects

This question already has an answer here:

Are 'Arrow Functions' and 'Functions' equivalent / exchangeable? 1 answer

I'm completely stumped on this. I have three elements on the page with a class of .topic-link.

<div id="parent1"> <a href="#" class="topic-link"></a> </div> <div id="parent2"> <a href="#" class="topic-link"></a> </div> <div id="parent3"> <a href="#" class="topic-link"></a> </div>

I can run $('.topic-link').eq(0).parent(); in the JS console and get the correct parent returned. But when I iterate over them I get an empty object each time.

$('.topic-link').each( () => { console.log($(this).parent()); }); // returns 3 empty objects

最满意答案

箭头函数没有自己的this所以你有什么不等于

$('.topic-link').each(function () { console.log($(this).parent()); });

在你的情况下， this是window （或document或任何取决于范围调用），没有父节点

Arrow functions don't have their own this so what you have is not equivalent to

$('.topic-link').each(function () { console.log($(this).parent()); });

In your case this is window (or document or whatever depending on scope it is called in) which has no parent dom node