Call

A call is the usage action of a definition or declaration.

For example, a function is declared, then called. Calling an undefined structure is a fatal error.

A definition must happen before a call. The autoload process allows for last minute loading of a class definition.

<?php

function foo() {}

// calling a function
foo();

// calling an undefined function
goo();
Fatal error: Uncaught Error: Call to undefined function goo()


?>

Related : Definition, Class Autoloading