I have strings like, $a = 'helloMister'; $b = 'doggyWaltz'; $c = 'bumWipe'; $d = 'pinkNips'; How can I explode at the capital letters, search on google for some time and came back with nothing! Thanks. 解决： If you want to split helloMister into hello and Mister you can use preg_split to split the string at a point just before the uppercase letter