php explode at capital letters?

Question

I have strings like:

$a = \'helloMister\';
$b = \'doggyWaltz\';
$c = \'bumWipe\';
$d = \'pinkNips\';

How can I explode at the capital lette

Answer 1

Extending Mathew's Answer, this works perfectly,

$arr = preg_replace("([A-Z])", " $0", $str);
$arr = explode(" ",trim($arr));