javascript - 在JavaScript中存储key => value数组的最佳方法？(Best way to store a key=>value array in JavaScript?)

Question

What's the best way to store a key=>value array in javascript, and how can that be looped through?(在javascript中存储key=>value数组的最佳方法是什么，以及如何循环？)

The key of each element should be a tag, such as {id} or just id and the value should be the numerical value of the id.(每个元素的键应该是一个标记，例如{id}或只是id ，值应该是id的数值。)

It should either be the element of an existing javascript class, or be a global variable which could easily be referenced through the class.(它应该是现有javascript类的元素，或者是可以通过类轻松引用的全局变量。)

jQuery can be used.(可以使用jQuery。)

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Answer 1

That's just what a JavaScript object is:(这就是JavaScript对象：)

var myArray = {id1: 100, id2: 200, "tag with spaces": 300};
myArray.id3 = 400;
myArray["id4"] = 500;

You can loop through it using for..in loop :(你可以使用for..in循环for..in它：)

for (var key in myArray) {
  console.log("key " + key + " has value " + myArray[key]);
}

See also: Working with objects (MDN).(另请参阅： 使用对象 （MDN）。)

In ECMAScript6 there is also Map (see the browser compatibility table there):(在ECMAScript6中还有Map （参见那里的浏览器兼容性表）：)

• An Object has a prototype, so there are default keys in the map.(Object有一个原型，因此地图中有默认键。)

  This could be bypassed by using map = Object.create(null) since ES5, but was seldomly done.(这可以通过使用自ES5以来的map = Object.create（null）来绕过，但很少完成。)

• The keys of an Object are Strings and Symbols, where they can be any value for a Map.(Object的键是字符串和符号，它们可以是Map的任何值。)

• You can get the size of a Map easily while you have to manually keep track of size for an Object.(您必须手动跟踪对象的大小，才能轻松获得Map的大小。)