Failide lisamine PHP-s

Oletame, et meil on üks fail:

index.php<?php
  echo 'index';
?>

Oletame, et on ka teine fail:

test.php<?php
  echo 'test';
?>

Paneme teise faili sisu esimesse faili. See tehakse operaatori include abil:

index.php<?php
  include 'test.php';
  echo 'index';
?>

Sama faili saab lisada mitu korda:

index.php<?php
  include 'test.php';
  include 'test.php';
  include 'test.php';
  
  echo 'index';
?>