<?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; } } ?>

<?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.'、'; } ?>