PHP - Remove excess Whitespace but not new lines

问题

i was looking for a way to remove excess whitespaces from within a string (that is, if 2 or more spaces are next each other, leave only 1 and remove the others), i found this Remove excess whitespace from within a string and i wanted to use this solution:

$foo = preg_replace( '/\s+/', ' ', $foo );

but this removes new lines aswell, while i want to keep them. Is there any way to keep newlines while removing excess whitespace?

回答1:

http://www.php.net/manual/en/regexp.reference.escape.php defines \h any horizontal whitespace character (since PHP 5.2.4) so probably you are looking for

$foo = preg_replace( '/\h+/', ' ', $foo );

example: http://ideone.com/NcOiKW

回答2:

if you want to remove excess of only-spaces (not tabs, new-lines, etc) you could use HEX code to be more specific:

    $text = preg_replace('/\x20+/', ' ', $text);

来源：https://stackoverflow.com/questions/16725894/php-remove-excess-whitespace-but-not-new-lines