Variable scope
Variable scope
The scope of a variable is the context within which it is defined. For the most part all PHP variables only have a single scope. This single scope spans included and required files as well. For example:
<?php $a = 1; include 'b.inc'; ?>
Here the $a variable will be available within the included b.inc script. However, within user-defined functions a local function scope is introduced. Any variable used inside a function is by default limited to the local function scope. For example:
<?php $a = 1; /* global scope */ function test() { echo $a; /* reference to local scope variable */ }