check if string has certain character php

$myString = 'Hello Bob how are you?';
if (strpos($myString, 'Bob') !== false) {
    echo "My string contains Bob";
}$result = strpos("haystack", "needle");

if ($result != false)
{
  // text found
}$mystring = 'abc';
$findme   = 'a';
$pos = strpos($mystring, $findme);