PHP Spotting References

Introduction

Many syntax constructs in PHP are implemented via referencing mechanisms. If reference to a global variable is unset in a function, the same variable in global namespace is not removed.

Example

 Live Demo

<?php $var1 = 'Hello World'; function myfunction(){    global $var1;    $var2 =&$var1;    echo "$var1, $var2 
";    $var2="Hello PHP";    echo "$var1, $var2 
";    unset($var1); } myfunction(); echo "$var1
"; ?>

Output

Global $va1 is intact.

Hello World, Hello World Hello PHP, Hello PHP Hello PHP

debug_zval_dump() function can be used if a variable has references to other variables