javascript对象中字符串键的单引号

Question

In nodejs I was creating a list of objects with each object supposed to have a string key and a number as value. I am able to create this without issues but while trying to log this with console.log() . I could see some keys did not have a single quotes surrounding the key while some did.

eg

[
    { '2d22f294': 0 },    
    { b6d108da: 0 },
    { b17562ff: 0 },
    { '0e4a0beb': 0 }
  ]

Could anyone explain what does it mean to have a single quotes surrounding the key , I was of the assumption this meant the key was a string but even the ones without single quotes around the keys are strings and act like strings.

Answer 1

如果它以数字开头，则打印必须向您显示有效的 javascript 并且引号告诉您它是一个字符串。

Answer 2

If you have an object like this

let object = {
    name: 'Jim',
    25: 'Age'
}

You can access the properties in the following way:

• for the name key ... object.name or object['name'] .

• for the key 25 ... object[25] or object['25']

This is because properties cannot start with a number in js. Therefore you have to access them with brackets.