php class require_once code example

Example 1: php require vs require_once

//The require statement has two variations, require and require_once.
//The require/require_once statement is used to include file.

// Require a file to be imported or quit if it can't be found
<?php
 require 'requiredfile.php';
?>
// Require_once is ignored if the required file has already been added by any of the include statements.
<?php
 require_once 'require_oncefile.php';
?>

Example 2: php requuire once

require_once('var.php');

Example 3: php require

// Require a file to be imported or quit if it can't be found
<?php
 require 'somefile.php';
?>
  
// Alternatively: Include a file, if it can't be found: continue.
<?php
include 'vars.php';
?>