It is possible to break binding between the content and variable by using unset() function. The unset() function doesn't destroy the content but only decouples variable from it.
<?php $a=10; $b=&$a; echo "before unsetting : ", $a, " " ,$b, PHP_EOL; unset($b); echo "after unsetting :" . $a . " "; $b=20; echo $b; ?>
After unsetting, $b can be used as normal vaiable
before unsetting : 10 10 after unsetting : 10 20
Reference can also be removed by assigning variable to NULL
<?php $x=100; $y=&$y; echo "x and y are references ", $x, " " ,$y, PHP_EOL; $y=NULL; $x=200; echo "x: ", $x . " y: " ,$y, PHP_EOL; ?>
Result of above script is as follows
x and y are references 100 x: 200 y: