<!DOCTYPE html>
<html>
<body>
<?php
echo substr_compare("Hello world!","Hello world!",0)."<br>"; // the two strings are equal
echo substr_compare("Hello world!","Hello",0)."<br>"; // string1 is greater than string2
echo substr_compare("Hello world!","Hello world! Hello!",0)."<br>"; // string1 is less than string2
?>
</body>
</html>