- strpos: documentation ( source)
<?php
$mystring = 'abc';
$findme = 'a';
$pos = strpos($mystring, $findme);
print "answer finding a in abc: " . $pos . "\n" ;
$mystring = 'abc';
$findme = 'z';
$pos = strpos($mystring, $findme);
print "answer finding z in abc: " . $pos . "\n" ;