check if character is in string php

$myString = 'Hello Bob how are you?';
if (strpos($myString, 'Bob') !== false) {
    echo "My string contains Bob";
}$mystring = 'abc';
$findme   = 'a';
$pos = strpos($mystring, $findme);if (strpos($haystack,$needle) !== false) {
    echo "$haystack contains $needle";
}// returns true if $needle is a substring of $haystack
function contains($haystack, $needle){
    return strpos($haystack, $needle) !== false;
}