Is it valid to define functions in JSON results?

json anonymous-function
Zachary Scott picture Zachary Scott · Jan 4, 2010 · Viewed 101.4k times · Source

Part of a website's JSON response had this (... added for context):

{..., now:function(){return(new Date).getTime()}, ...}

Is adding anonymous functions to JSON valid? I would expect each time you access 'time' to return a different value.

Answer

Mike picture Mike · Jan 4, 2010

No.

JSON is purely meant to be a data description language. As noted on http://www.json.org, it is a "lightweight data-interchange format." - not a programming language.

Per http://en.wikipedia.org/wiki/JSON, the "basic types" supported are:

  • Number (integer, real, or floating point)
  • String (double-quoted Unicode with backslash escaping)
  • Boolean (true and false)
  • Array (an ordered sequence of values, comma-separated and enclosed in square brackets)
  • Object (collection of key:value pairs, comma-separated and enclosed in curly braces)
  • null

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