What Is JavaScript JSON Object?

The JSON object is a built-in object in the JavaScript engine that offers 2 functions to parse and generate JSON text strings:

1. JSON.parse() - Parses a text string from a JSON text string, constructs the JavaScript value. An optional reviver function can be provided to perform a transformation on the resulting object before it is returned.

2. JSON.stringify() - Converts a JavaScript value to a JSON text string, An optional replacer function is specified to replace some values.

Here is a JavaScript code example, JSON-Hello.html, that shows you how to use the built-in JSON object:

<!-- JSON-Hello.html
     Copyright (c) FYIcenter.com 
-->
<html>
<body>
<script type="text/javascript">
   var object = {"msg":"Hello World!"};
   var str = JSON.stringify(object);

   document.write("<p>JSON text string from JSON.stringify():</p>");
   document.write("<pre>str = "+str+"</pre>");

   var val = JSON.parse(str);
   document.write("<p>Value from JSON.parse():</p>");
   document.write("<pre>val.msg = "+val.msg+"</pre>");
</script>
</body>
</html>

Open this example, JSON-Hello.html, in a Web browser. You see the following:

JSON text string from JSON.stringify():
   str = {"msg":"Hello World!"}

Value from JSON.parse():
   val.msg = Hello World!

⇒ JSON.parse() Function in JavaScript

⇐ Using JSON in JavaScript

⇑ Using JSON in JavaScript

⇑⇑ JSON Tutorials