javascript - 在 JavaScript 中存储 key=>value 数组的最佳方法？

Question

在 javascript 中存储 key=>value 数组的最佳方法是什么，如何循环？

每个元素的key应该是一个标签，比如{id}或者只是id，value应该是id的数值。

它应该是现有 javascript 类的元素，或者是可以通过该类轻松引用的全局变量。

可以使用jQuery。

Answer 1

这就是 JavaScript 对象:

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

您可以使用 for..in loop 循环遍历它:

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

另请参阅:Working with objects (MDN)。

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. This could be bypassed by using map = Object.create(null) since ES5, but was seldomly done.

• The keys of an Object are Strings and Symbols, where they can be any value for a Map.

• You can get the size of a Map easily while you have to manually keep track of size for an Object.