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