两个简单的php设计模式

8870188

1.单例模式
不管多少次实例化类，都只有一个实例存在，适合数据库操作
<?php
class my{
public static $_instance = NULL;
public static function getInstance(){
if(self::$_instance == NULL)
self::$_instance = new self();
return self::$_instance;
}
public function red(){
echo "red";
}
public function __construct(){
echo 1;
}
}
$db = My::getInstance();
$db->red();
$mm = My::getInstance();
$mm->red();
?>
运行结果：两个对象，执行一次构造方法
2.工厂模式
不同处理对象，内部自动分流处理，但对用户来说，只有一个方法，简单方便
interface Hello{
function say_hello();
}
class English implements Hello{
public function say_hello(){
echo "Hello!";
}
}
class Chinese implements Hello{
public function say_hello(){
echo "你好";
}
}
class speak{
public static function factory($type){
if($type == 1) $temp = new English();
else if($type == 2) $temp = new Chinese();
else{
die("Not supported!");
}
return $temp;
}
}
$test = Speak::factory(1);
$test->say_hello();