JavaScript Object Notation (JSON)

JavaScript Object Notation (JSON) is a data-interchange format. JSON text format is familiar to programmers of many languages. JSON object is a valid JS, so it can be used directly.
JSON structures:

1. {Key1: value1, Key2: value2,…}
2. [Value1, value2,…]

Key can be string. This can take any characters except ", \ and control-characters.

Value can be string, number, object, array, true, false, and null. So it can represent complex structure.

JSON application is useful at many places. It can be used as an alternative to XML. In AJAX application JSON is very useful alternative of XML. JSON can be used for transmitting structured data over network in serialized format. JSON is language independent so it is available in your PHP also.