<!DOCTYPE html>
<html>
<body>
<?php
echo substr_compare("Hello world!","Hello world!",0)."<br>"; // 两字符串相等
echo substr_compare("Hello world!","Hello",0)."<br>"; // string1 大于 string2
echo substr_compare("Hello world!","Hello world! Hello!",0)."<br>"; // string1 小于 string2
?>
</body>
</html>