Regex to split a string only by the last whitespace character

Question

hopefully this should be a quick and simple one, using PHP I\'m trying to split a string into an array but by only the last instance of whitespace. So far I have...

Answer 1

If the * and + after \S dupicated? Only /\s+(?=\S+$)/ or /\s+(?=\S*$)/ is enough depends on the need.