for example my json string is like this :
{
"v1" : [],
"v2": 2,
"v3": f()
}
Now the context in which I need to decode this has a definition of f and f() gives right answer in that context(checked via debugger). But JSON.parse(jsonstring) gives me Unexpected token. eval also gives error. What should I do?
See an example Here
Why it does not work
Look at the definition of a JSON, it can not contain function calls.
Possible workarounds
One way is to do something like this, return a string of the function you want to call.
{
"v1" : [],
"v2": 2,
"v3": "f"
}
Now when you need to access it, you can call the function.
var myJSON = JSON.parse(jsonstring);
var myFunctionResult = window[myJSON.v3](); //works if global variable
Other option is to change how your code works and make an async script call [jQuery would be getScript, regular JavaScript createElement("script") with appendChild() and use a callback like JSONP does.
JSON strings cannot contain functions.
JSON is not the same things as a JavaScript object, even though the former is derived from the latter. Ultimately, it is a string.
You should not use any callbacks or function calls in JSON (It is not valid JSON, it is insecure and it is absurd - two last things if you somehow make it work) , there is always way to do it in script.
EDIT: You REALLY don't need to call function from JSON - please return back to "drawing board" and design app to not use this pattern
