php explode string with Uppercase if lowercase letter exists before it without space

Question

$str=\"Hello MotoBell RingsKing Speech\";

I need explode this string by uppercase letter if lowercase letter exists before it.

like this:

Answer 1

var_dump(preg_split('/(?<=[a-z])(?=[A-Z])/', 'Hello MotoBell RingsKing Speech'))

// array(3) {
//   [0]=>
//   string(10) "Hello Moto"
//   [1]=>
//   string(10) "Bell Rings"
//   [2]=>
//   string(11) "King Speech"
// }