php 設計模式之 單例模式

小船類boat.php 複製代碼 代碼如下:<?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;
}
/**
* 設定船長
*
* @param unknown_type $name
*/
public function setSkipper($name){
$this->skipper=$name;
}
/**
* 裝人
*
* @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!';
}
}
/**
* 船上裝了什麼人
*
* @return unknown
*/
public function whoInBoat(){
return $this->passengers;
}
}
?>

現在看看怎麼樣上客複製代碼 代碼如下:<?php
include 'boat.php';
echo "從前有一條河，河裡只有一條船，<br>";
$boat1=boat::getInstance();//因為只有一條船，所以只有一個執行個體
echo "現在張三要到河東去,";
$boat1->load('張三');
echo "<br>現在船上坐著：<br>";
foreach ($boat1->whoInboat() as $who){
echo $who.'<br>';
}
echo "<br>現在李四也要過河東去<br>";
$boat1->load('李四');
echo "現在船上坐著：<br>";
foreach ($boat1->whoInboat() as $who){
echo $who.'、';
}
echo "<br><br>王五以為這條河有另一條船,<br>";
$boat2=boat::getInstance();
echo "他現在上船<br>";
$boat2->load('王五');
echo "現在船上坐著：<br>";
foreach ($boat1->whoInboat() as $who){
echo $who.'、';
}
?>