if text contains word then in php

1$myString = 'Hello Bob how are you?';
2if (strpos($myString, 'Bob') !== false) {
3    echo "My string contains Bob";
4}

1if (strpos($haystack,$needle) !== false) {
2    echo "$haystack contains $needle";
3}

1$mystring = 'abc';
2$findme   = 'a';
3$pos = strpos($mystring, $findme);

1// returns true if $needle is a substring of $haystack
2function contains($haystack, $needle){
3    return strpos($haystack, $needle) !== false;
4}