Replace all characters except letters, numbers, spaces and underscores [closed]

Answer 1

I normally use something like:

$string = preg_replace("/[^ \w]+/", "", $string);

That replaces all non-space and non-word characters with nothing.

Answer 2

[^0-9a-zA-Z_\s] 

is what you want to replace.

Answer 3

<?php
$string = 'April 15, 2003';
$pattern = '/[^\w ]+/';
$replacement = '';
echo preg_replace($pattern, $replacement, $string);
?>