php 设计模式之 单例模式

　　小船类boat.php
复制代码 代码如下:
<?php
class boat {
private static $instance=null;
private $skipper;
private $personNum=0;
private $passengers=array();
private function __construct() {
}
public static function getInstance(){
if (self::$instance==null){
self::$instance=new boat();
}
return self::$instance;
}
/**
* 设置船长
*
* @param unknown_type $name
*/
public function setSkipper($name){
$this->skipper=$name;
}
/**
* 装人
*
* @param unknown_type $person
*/
public function load($person){
if (!emptyempty($person) and $this->personNum<=5){
array_push($this->passengers,$person);
$this->personNum=$this->personNum+1;
}
if ($this->personNum>5) {
echo this boat only load 5 person!;
}
}
/**
* 船上装了什么人
*
* @return unknown
*/
public function whoInBoat(){
return $this->passengers;
}
}
?>

现在看看怎么样上客
复制代码 代码如下:
<?php
include boat.php;
echo 从前有一条河，河里只有一条船，<br>;
$boat1=boat::getInstance();//因为只有一条船，所以只有一个实例
echo 现在张三要到河东去,;
$boat1->load(张三);
echo <br>现在船上坐着：<br>;
foreach ($boat1->whoInboat() as $who){
echo $who.<br>;
}
echo <br>现在李四也要过河东去<br>;
$boat1->load(李四);
echo 现在船上坐着：<br>;
foreach ($boat1->whoInboat() as $who){
echo $who.、;
}
echo <br><br>王五以为这条河有另一条船,<br>;
$boat2=boat::getInstance();
echo 他现在上船<br>;
$boat2->load(王五);
echo 现在船上坐着：<br>;
foreach ($boat1->whoInboat() as $who){
echo $who.、;
}
?>