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

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Closed last year.

I am looking to replace all characters in a string except letters, numbers, spaces and underscores.

Could someone please provide a example?

回答1:

I normally use something like:

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

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

回答2:

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

is what you want to replace.

回答3:

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

来源：https://stackoverflow.com/questions/6442174/replace-all-characters-except-letters-numbers-spaces-and-underscores