PHP Include & Include_once

PHP Include Statement

• PHP Include statement is a file inclusion statement.
• Which used to add another text or code file into where you applied this include statement.
• Include statement is very useful that you have many pages contains the same code.
• So you can write a new file of this code and include every page to need this.
• Include statement includes file-based on the path of a file If file path did not give It checks in the calling script's own directory and the current working directory before failing.

Syntax of the php include the statement

Understand the include statement from this example:

1. A file named is 'home2.php'.

<?php

   echo "Hello this is home 2 script";
   echo "<br/>";
	
?>

2. The second file named is 'home.php'.

<?php

   echo "Hello this is the home page script";
   echo "<br/>";
   
   include "home2.php";    // file 'home2.php' included on this line and file code is being executed in this script
	
?>

Output :

PHP Include_once Statement

PHP Include_once statement checks that It is to be include script is already included or not the entire script.

Understand the include_once statement from this example

 
1. A file named is 'home2.php'.

<?php

   echo "Hello this is home 2 script";
   echo "<br/>";
	
?>

2. The second file named is 'home.php'.

<?php

   include "home2.php";   //file included here

   echo "Hello this is home page script";
   echo "<br/><br/>";
   
   include_once "home2.php";   // Checks 'home2.php' is already included, If included this inclusion will be skip.
	
?>