How to prepend a hyphen to uppercase characters in a string

[AppsRU]

I wondered if there was a short way to place a hyphen before every capital letter in a string except the first capital?

If string is OneTwoThree I need it to read One-Two-Three

Tnx

[jscheuer1]

There may or may not be a shortcut method, and/or a more efficient way of putting together existing methods, but this works:

<?php
$string = 'OneTwoThree';
$shortstrings = array(substr($string, 0, 1), substr($string, 1));
$shortstrings[1] = preg_replace("/([A-Z])/", "-$1", $shortstrings[1]);
$newstring = implode('', $shortstrings);
echo $newstring;
?>

If you're turning it into a function, you should test to make sure $string is a string and has a strlen of at least 2. Like:

<?php
$mystring = 'OneTwoThree';
function hypenatecaps($string){
    if(!is_string($string)){return;}
    if(strlen($string) < 2){
        return $string;
    }
    $shortstrings = array(substr($string, 0, 1), substr($string, 1));
    $shortstrings[1] = preg_replace("/([A-Z])/", "-$1", $shortstrings[1]);
    $newstring = implode('', $shortstrings);
    return $newstring;
}
echo hypenatecaps($mystring);
?>

This also works:

<?php
$string = 'OneTwoThree';
echo substr($string, 0, 1) . preg_replace("/([A-Z])/", "-$1", substr($string, 1));
?>

[AppsRU]

Thanks John!

I'm just splitting file names and also found this works nice.

function splitAtUpperCase($s) {

return preg_replace(‘/(?<!^)([A-Z])/', '-\\1', $s);
}
echo splitAtUpperCase($s);

[jscheuer1]

Please don't link to other sites unnecessarily.

return preg_replace(‘/(?<!^)([A-Z])/', '-\\1', $s);

Will not work because of the non-standard quote (red in the above). But it's a good concept. And using a standard quote fixes it:

return preg_replace('/(?<!^)([A-Z])/', '-\\1', $s);