JSON Response Format
To return an API response in JSON format, send a parameter “format” in the request with a value of “json”. If you are using the JavaScript method JSONP you can also send the parameter “callback” in the request with a value of the name you want to call back function to be.
JSON, or JavaScript Object Notation, is a simple machine-readable data-interchange format, which makes constructing API applications in JavaScript easy (though it can be used from other languages too!). For more information about JSON, visit json.org.
To return an API response in JSON format, send a parameter "format" in the request with a value of "json".
A method call returns this:
If an error occurs, the following is returned:
You can see a demo response here.
To return an API response in JSON format with a callback function, send a parameter "format" in the request with a value of "json" and "callback" with a value of "yourcallbackfunction".
You can see a demo response here.

