PHP match specific letters of sentence and get only the words

Question

I'm tiring to write a PHP code for get matched words by using letters, its not the same strpos.

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


 in this  "$string" when i search "$searchletters" i need to get 
 the word "you" which have you letters, 

anyone have a idea how to implement this with PHP. Thank 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

Answer 2

strtok(strrchr($string,$searchletters), " ");

Explanations:

strrchr() : finds the position of the last occurrence of a string within another string, and returns all characters from this position to the end of the string.

strtok() : which can be used to split a string into smaller strings (tokens) based on some separator(s). For more details and examples, see the strtok PHP manual page