The "JSON" Object Type - parse() and stringify()

This section provides a quick description and a tutorial example script on the 'JSON' built-in object type, which is used to parse JSON strings to create JavaScript structured values and convert JavaScript structured values to JSON strings.

The JSON object type that offers 2 static 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.html, that shows you how to use the built-in JSON object:

<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.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!

Table of Contents

 About This Book

 Introduction to JavaScript

 ECMAScript Language Specification and JavaScript Dialects

 Data Types, Variables and Expressions

 Flow Control Statements

 Creating, Accessing, and Manipulating Arrays

 Defining and Calling Functions

 Web Browser Supporting JavaScript

 Server-Side and Client-Side Web Scripting

 Introduction to Objects

 Defining Your Own Object Types

 Inheritance of Properties and Methods through the Prototype Object Chain

 'jrunscript' - JavaScript Shell Command from JDK

 Using Functions as "Function" Objects

Introduction to Built-in Object Types

 Overview of Built-in Object Types

 The "Object" Object Type - The Root Object Type

 The "Global" Object Type - The Invisible Global Container

 Global Properties and Functions Defined in ECMAScript

 Global Properties and Functions Provided by "jrunscript"

 The "Function" Object Type - Functions Are Objects

 The "Array" Object Type - Arrays Are Objects

The "JSON" Object Type - parse() and stringify()

 The "String" Object Type - Not Equal to String Primitive Type

 The "Boolean" Object Type - Wrapping Boolean Values into Objects

 The "Number" Object Type - Not Equal to Number Primitive Type

 The "Date" Object Type - Managing Dates and Times

 The "RegExp" Object Type - Regular Expression Patterns

 The "Error" Object Type - Runtime Exceptions

 The "Math" Object Type - The Math Container

 W3C's Document Object Model (DOM) Specifications

 References

 Full Version in PDF/EPUB