string - How can strip whitespaces in PHP's variable?

Question

I know this comment PHP.net. I would like to have a similar tool like tr for PHP such that I can run simply

tr -d " " ""

I run unsuccessfully the function php_strip_whitespace by

$tags_trimmed = php_strip_whitespace($tags);

I run the regex function also unsuccessfully

$tags_trimmed = preg_replace(" ", "", $tags);

Answer 1

To strip any whitespace, you can use a regular expression

$str=preg_replace('/s+/', '', $str);

See also this answer for something which can handle whitespace in UTF-8 strings.