Match whole word in a sentence that starts with specific letters

Question

I'm tried to write PHP code for matching words by using letters, but my task is not satisfied by strpos(). I need to match the whole word which starts with the needle string.

$string = "How are you robin ?";
$searchletters = "yo";

Desired result: you

Answer 1

You can use this regex:

$re = '/\b' . preg_quote($searchletters, '/') . '\w*\b/';

preg_match($re, $string, $m);
echo $m[0] . "\n";
//=> you

RegEx Demo