php设计模式之面向接口开发实例代码

<?php
header("Content-type:text/html;charset=utf-8");
/**
* 共同接口
*/
 interface db
{
    function conn();
}

/**
* mysql类
*/
class DbMysql implements db
{
    public function conn()
    {
        echo "连接上了mysql";
    }
}

/**
* sqlite类
*/
class DbSqlite implements db
{
    public function conn()
    {
        echo "连接上了sqlite";
    }
}

$db = new DbMysql();
$db->conn();

$db = new DbSqlite();
$db->conn();