What is Constants in PHP and it use?
Defining a Constant in PHP will help you if you are going to use a value through out your script. And as the name says CONSTANT means it’s a static value which cannot be changed.
To define a Constant in PHP all you have to do is use the default PHP function define()
Here is the example:
<?php
define("WEBSITE", "tutorialsmade.com");
echo WEBSITE;
?>How this will be useful?
Lets take this example, you have a common PHP script and you are going to use it for several different domains:
1. exampleone.come
<?php
define('WEBSITE', 'http://exampleone.com');
?>
<html>
<body>
<img src="<?php echo WEBSITE; ?>/images/1.jpg" />
<a href="<?php echo WEBSITE; ?>/page/one.html" />
</body>
<html>2. exampletwo.com
<?php
define('WEBSITE', 'http://exampletwo.com');
?>
<html>
<body>
<img src="<?php echo WEBSITE; ?>/images/1.jpg" />
<a href="<?php echo WEBSITE; ?>/page/one.html" />
</body>
<html>So, the above two examples shows, the only value we have to change is the Constant ‘WEBSITE’, all the other places it will take the value automatically.