有没有办法使用数字类型作为对象键？ [英] Is there any way to use a numeric type as an object key?

问题描述

似乎当我在对象中使用数字类型作为键名时，它总是被转换为字符串。反正有没有把它作为数字存储？正常的类型转换似乎不起作用。

It seems that when I use a numeric type as a key name in an object, it always gets converted to a string. Is there anyway to actually get it to store as a numeric? The normal typecasting does not seem to work.

示例：

var userId = 1;
console.log( typeof userId ); // number
myObject[userId] = 'a value';
console.dir(myObject);

Dir输出：

{
    '1': 'a value'
}

我想要的是：

{
    1: 'a value'
}

建议？

谢谢

推荐答案

不，这是不可能的。 密钥将始终转换为字符串。请参阅属性访问者文档

No, this is not possible. The key will always be converted to a string. See Property Accessor docs

属性名称必须是字符串。这意味着非字符串对象不能用作对象中的键。任何非字符串对象（包括数字）都通过toString方法转换为字符串。

Property names must be strings. This means that non-string objects cannot be used as keys in the object. Any non-string object, including a number, is typecasted into a string via the toString method.

> var foo = {}
undefined

> foo[23213] = 'swag'
'swag'

> foo
{ '23213': 'swag' }

> typeof(Object.keys(foo)[0])
'string'

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