replacing all uppercase words by ucword

Question

I am having small problem. I am trying to replace words in sentence ie

HELLO World WHAT

by

Hello World What

so far have way to detecting it:

preg_replace('/(\b[A-Z][A-Z]+\b)/sm','$1', $string);

but it does nothing as I can't put as an argument ucwords('$1').

Any help would be great.

cheers, /Marcin

PS this kind of methods are not good: ucwords(strtolower($string)); as I want to leave all what wasn't all caps as it was.

Answer 1

How about using:

ucwords(strtolower($string));

You can combine this approach with the e modifier:

preg_replace('/(\b[A-Z][A-Z]+\b)/sme','ucwords(strtolower($1))', $string);

Answer 2

It is slightly more efficient to use an anonymous function rather then call on the /e modifier.

   $formatted = preg_replace_callback(
        '/(\b[A-Z][A-Z]+\b)/',
        create_function(
            '$matches',
            'return ucwords(strtolower($matches[0]));'
        ),
        $string
    );