PHP Constant

define() -

In PHP, we declare constant by define() or The define() function defines a constant.

Syntax

<?php define(name,value,TRUE or FALSE(optional)); ?>

Parameter	Desryption
Name	Represents the name of constant
value	Represents the value of constant
Optional	In optional parameter we use true and falsevalue if we enter TRUE constant remain case-insensitive otherwise constant will case-sensitive.

Example

<?php define('test','Hello how are you?'); echo constant('test'); ?>

Output :

Hello how are you? 



Example

<?php define('rex','my name is rex'); echo rex; ?>

Output :

my name is rex

Note -

PHP constants are similar as php variable and little more permanent.
• The value of constant can not changed after assigned.
• It can hold value only strings and numbers.
• we do not use $ sign with constant name.
• It can hold value only strings and numbers.