JSON property name why double quotes (personal guessing) _javascript tips

Reason one:

More standardized, conducive to interpretation

Reason two:

Avoid incompatible problems with keywords such as class

Reason three:

Perhaps the most obscure:

var a = 00; var B = {00:12}; A in B; --> true
var a = 0; var b = {' A ': A in B;--> false

Personal guess if the property name of a JS object is not a string, the type conversion is first, but the unexpected value may occur in the process, although it is only an example, but it is necessary to develop a good habit.