removing all but one space from a string

[jumpenjuhosaphat]

Okay, I've seen this done before, but I can't seem to find it in the search engines again.

I need to check to see if there is more than one space in a users input, and if there is, I need to remove the extra spaces, leaving only the one.  Can someone tell me how to do this please?

[Jessica]

php.net/trim will take off spaces in the end.
php.net/substr-count will tell you the number of a substr in a string.
http://us2.php.net/manual/en/ref.strings.php

[jumpenjuhosaphat]

Yeah, I don't need to trim it, and I got substr_count, but that doesn't remove the spaces, it just counts them.  I could use str_replace, but that would replace all instances of the substring.  I want all but one replaced.

[Jessica]

Which one?

[ShogunWarrior]

Do you mean like [b]firstname(space)(space)secondname(space)(space)(space)thirdname[/b] would simply become [b]firstname(space)secondname(space)thirdname[/b]? I.E: Should it collapse extra spaces into single spaces?

[jumpenjuhosaphat]

Yes, exactly.  I'm trying to validate UK post codes, and 1 space is required in UK post codes.  If the user enters any more than that, an error is returned.

[Crimpage]

You can count them with substr_count($haystack, ' ') or you could use a regular expression to do that...  I just searched google for "Regular Expression UK Postcode" and a lot of info came up.

Cheers,
Dave

[kenrbnsn]

You can explode the string on a space, use the [url=http://www.php.net/array_filter]array_filter()[/url] function to remove all spaces from the result of the explode and use implode to put it back together again:
[code]<?php
function not_space($v) {
if ($v != ' ') return($v);
}
$str = 'This string    has    multiple  spaces    in it.';
$str2 = implode(' ',array_filter(explode(' ',$str),'not_space'));
echo '<pre>$str:' . $str . '<br>$str2:' . $str2 . '</pre>';
?>[/code]

Ken

[jumpenjuhosaphat]

Thanks for your help everyone.  Here's what I found:

[code]
preg_replace('/\s\s+/', ' ', $str);
[/code]

If there is more than one instance of a space in the string, this will remove all of them but one.