php regex: removing more than double space

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

that will remove more than just one space ?

i need开发者_StackOverflow社区 to remove anything more than double space.

I'm taking "more than double space" to mean 3 or more spaces:

$tags = preg_replace('/\s{3,}/',' ', $tags);

This will replace 3 or more contiguous occurrences of any whitespace character with a single space.

So you want to replace a sequence of 2 or more spaces with a single space? What you've got there is pretty much it, except that it will match any whitespace (tabs, etc) not just spaces.