javascript - Which characters are valid/invalid in a JSON key name?

ID : 20018

viewed : 16

Tags : javascriptjsonobjectkeyjavascript

Top 5 Answer for javascript - Which characters are valid/invalid in a JSON key name?

vote vote

98

No. Any valid string is a valid key. It can even have " as long as you escape it:

{"The \"meaning\" of life":42} 

There is perhaps a chance you'll encounter difficulties loading such values into some languages, which try to associate keys with object field names. I don't know of any such cases, however.

vote vote

86

The following characters must be escaped in JSON data to avoid any problems:

  • " (double quote)
  • \ (backslash)
  • all control characters like \n, \t

JSON Parser can help you to deal with JSON.

vote vote

70

It is worth mentioning that while starting the keys with numbers is valid, it could cause some unintended issues.

Example:

var testObject = {     "1tile": "test value" }; console.log(testObject.1tile); // fails, invalid syntax console.log(testObject["1tile"]; // workaround 
vote vote

68

Unicode codepoints U+D800 to U+DFFF must be avoided: they are invalid in Unicode because they are reserved for UTF-16 surrogate pairs. Some JSON encoders/decoders will replace them with U+FFFD. See for example how the Go language and its JSON library deals with them.

So avoid "\uD800" to "\uDFFF" alone (not in surrogate pairs).

vote vote

52

Top 3 video Explaining javascript - Which characters are valid/invalid in a JSON key name?

Related QUESTION?