<?php
/*
7. Write a PHP script to remove all characters from a string except a-z A-Z 0-9 or " ". Go to the editor
Sample string : abcde$ddfd @abcd )der]
Expected Result : abcdeddfd abcd der - See more at: http://www.w3resource.com/php-exercises/php-regular-expression-exercises.php#sthash.fzCJEK6c.dpuf
*/
$text = 'abcde$ddfd @abcd )der]';
$reg = "/[^a-zA-Z0-9]/";
print preg_replace($reg, "", $text);
?>