获取关联数组键的列表 [英] Getting a list of associative array keys

问题描述

我在 JavaScript 中有一个关联数组:

I have an associative array in JavaScript:

var dictionary = {
    "cats": [1,2,3,4,5],
    "dogs": [6,7,8,9,10]
};

我如何获得这本字典的键?即，我想要

How do I get this dictionary's keys? I.e., I want

var keys = ["cats", "dogs"];

---

只是为了使术语正确 - JavaScript 中没有关联数组"这样的东西 - 从技术上讲，这只是一个 object 并且它是我们想要的对象键.

---

Just to get the terminology correct - there is no such thing as an 'associative array' in JavaScript - this is technically just an object and it is the object keys we want.

推荐答案

您可以使用:Object.keys(obj)

示例:

var dictionary = {
  "cats": [1, 2, 37, 38, 40, 32, 33, 35, 39, 36],
  "dogs": [4, 5, 6, 3, 2]
};

// Get the keys
var keys = Object.keys(dictionary);

console.log(keys);

有关浏览器支持，请参阅下面的参考资料.它在 Firefox 4.20、Chrome 5 和 Internet Explorer 9 中受支持.Object.keys() 包含一个代码片段，如果您的浏览器不支持 Object.keys()，您可以添加该代码片段.

See reference below for browser support. It is supported in Firefox 4.20, Chrome 5, and Internet Explorer 9. Object.keys() contains a code snippet that you can add if Object.keys() is not supported in your browser.

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