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JS Tutorial

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JS Forms

JS Forms Forms API

JS Objects

Object Definitions Object Properties Object Methods Object Accessors Object Constructors Object Prototypes Object ECMAScript 5

JS Functions

Function Definitions Function Parameters Function Invocation Function Call Function Apply Function Closures

JS HTML DOM

DOM Intro DOM Methods DOM Document DOM Elements DOM HTML DOM CSS DOM Animations DOM Events DOM Event Listener DOM Navigation DOM Nodes DOM Collections DOM Node Lists

JS Browser BOM

JS Window JS Screen JS Location JS History JS Navigator JS Popup Alert JS Timing JS Cookies

JS AJAX

AJAX Intro AJAX XMLHttp AJAX Request AJAX Response AJAX XML File AJAX PHP AJAX ASP AJAX Database AJAX Applications AJAX Examples

JS JSON

JSON Intro JSON Syntax JSON vs XML JSON Data Types JSON Parse JSON Stringify JSON Objects JSON Arrays JSON PHP JSON HTML JSON JSONP

JS Examples

JS Examples JS HTML DOM JS HTML Input JS HTML Objects JS HTML Events JS Browser JS Exercises JS Quiz JS Certificate

JS References

JavaScript Objects HTML DOM Objects


JSON Data Types


Valid Data Types

In JSON, values must be one of the following data types:

  • a string
  • a number
  • an object (JSON object)
  • an array
  • a boolean
  • null

JSON values cannot be one of the following data types:

  • a function
  • a date
  • undefined

JSON Strings

Strings in JSON must be written in double quotes.

Example

{ "name":"John" }

JSON Numbers

Numbers in JSON must be an integer or a floating point.

Example

{ "age":30 }

JSON Objects

Values in JSON can be objects.

Example

{
"employee":{ "name":"John", "age":30, "city":"New York" }
}

Objects as values in JSON must follow the same rules as JSON objects.



JSON Arrays

Values in JSON can be arrays.

Example

{
"employees":[ "John", "Anna", "Peter" ]
}

JSON Booleans

Values in JSON can be true/false.

Example

{ "sale":true }

JSON null

Values in JSON can be null.

Example

{ "middlename":null }