PHP data types - NULL
w3hello.com logo
PHP Basics
What is PHP
PHP Introduction
PHP Basics
Install WAMP
Install PHP on Windows 7
PHP variables
PHP Syntax and Comments Overview
PHP Variable Types
Install PHP on Linux
Install PHP on Windows
PHP: String operator
PHP arrays
PHP Data Types - Arrays
PHP Array
PHP data types
PHP if statement
PHP: PDO
PHP if else statement
PHP assignment operators
PHP Quiz
PHP SimpleXML Parser
PHP Form
PHP Sending Emails
PHP return statement
PHP AJAX and XML
PHP Data Types - Booleans
PHP Multidimensional Array
PHP while statement
PHP File Upload
PHP Captcha
PHP break
PHP Indexed Array
PHP For C Developers
PHP declare statement
PHP Echo Vs Print Statement
PHP Append to File
PHP logical operators - AND, OR, XOR, NOT
PHP Read File
PHP Projects: Create an Opinion Poll Application
PHP XML Introduction
PHP Error Handling
PHP Concatenation Operators
PHP Indexed, Associative, and Multidimensional Arrays
PHP XML Expat Parser
PHP data types - NULL
about the PHP programming language in general
PHP File
PHP and AJAX
PHP Open File
PHP Design Patterns
PHP Useful Resources
PHP foreach loop
How Append a String in PHP
PHP $ and $$
PHP Cookies
PHP Array: Associative, Multidimensional
PHP comparison operators
PHP $_SERVER
PHP Simple XML GET
PHP - AJAX and PHP
PHP Include and Require
The pi() function
PHP Form Validation
PHP Switch Case Conditional Statements
PHP Mail
PHP Coding Standard
PHP Switch
PHP Form Introduction
PHP Loop: For, ForEach, While, Do While
PHP include statement
PHP Exception Handling
PHP Arrays Numeric, Associative and Multi-Dimensional
PHP Predefined Variables
PHP Control Structures: If else, Switch Case
PHP Constants
PHP Environment Setup Windows, Linux and Mac OS X
PHP switch statement
PHP Web Concepts Generating Dynamic Content
PHP Prepared Statements
PHP Ajax Auto Complete Search
PHP Date and Time
PHP Syntax Overview
PHP If, Else and Elseif Conditional Statements
PHP
What is PHP, and why do I need it?
PHP Server Side Form Validation
PHP Data Types : integers and floating point numbers
PHP Call By Reference
Sending Emails using PHP
Create RSS Feed in PHP
PHP Error Handling and Logging
PHP PayPal Integration
Free PHP Live Project Training in Real Time
PHP XML Parsers
Regular expressions in PHP
PHP and MySQL
Discuss PHP
PHP do while statement
PHP Get ID of Last Inserted Record
PHP Looping
PHP Basics
Previous : PHP XML Expat Parser Next : about the PHP programming language in general

PHP data types - NULL


Secondary
Nav

Description

The special NULL value represents a variable has no value (nonvalue or unvalue). It is similar to Python's" None" or Perl's "undef".

NULL is the only possible value of type NULL.

It identifies variables being empty or not and useful to differentiate between the empty string and null values of databases.

There is only one value of type NULL, and that is the case-insensitive keyword NULL.

The following is an example of using NULL.

Syntax to define php null type

<?php
$value = NULL;
?>

The following example $Var1 set to NULL and a subsequent if statement checks whether it is NULL or not.

Example :

<?php
$Var1;
if ($Var==NULL)
{
echo 'Welcome to w3hello.com';
}
?>

Output :

Welcome to w3hello.com

Previous : PHP XML Expat Parser Next : about the PHP programming language in general
© Copyright 2018 W3Hello Publishing Limited. All rights reserved.
Contact us | Sitemap