本文实例讲述了PHP实现的观察者模式。分享给大家供大家参考，具体如下：
<?php
//定义观察者调用接口
class transfer{
protected $_observers = array();
//注册对象
public function register($sub){
$this->_observers[] = $sub;
}
//外部统一调用
public function trigger(){
if(!empty($this->_observers)){
foreach($this->_observers as $observer){
$observer->update();
}
}
}
}
//观察者接口
interface obserable{
public function update();
}
//实现观察者
class listen implements obserable{
public function update(){
echo 'now first time you need to do listen<br/>';
}
}
class read implements obserable{
public function update(){
echo 'now first time you need to read<br/>';
}
}
class speak implements obserable{
public function update(){
echo 'now first time you need to speak<br/>';
}
}
class write implements obserable{
public function update(){
echo 'now first time you need to write<br/>';
}
}
$transfer = new transfer();
$transfer->register(new listen());
$transfer->register(new read());
$transfer->register(new speak());
$transfer->register(new write());
$transfer->trigger();
希望本文所述对大家PHP程序设计有所帮助。