摘要：<?php //单例模式案例class Father{}$Father1 = new Father;$Father2 = new Father;echo ($Father1 instanceof Father)? '是':'不是';echo "<br>";echo ($Father2 instanceof Father
<?php
//单例模式案例
class Father
{
}
$Father1 = new Father;
$Father2 = new Father;
echo ($Father1 instanceof Father)? '是':'不是';
echo "<br>";
echo ($Father2 instanceof Father)? '是':'不是';
echo "<br>";
echo ($Father1 === $Father2) ? '完全相等':'不相等';
echo "<br>";
var_dump($Father1,$Father2);
echo "<hr>";
//Mother只允许被实例化一次
class Mother{
//1. new 创建实例
//2. clone 克隆当前的实例
private function __construct(){} //构造器私有化
private function __clone(){}//克隆方法私有化
//创建类的内部静态属性，保存类的唯一实例
protected static $instance = null;
//创建一个外部接口，并返回当前类的唯一实例
public static function getInstance(){
if (is_null(static :: $instance)){
static :: $instance = new static();
}
return static :: $instance;
}
}
//从外部进行实例化
$Mother1 = Mother :: getInstance();
$Mother2 = Mother :: getInstance();
echo ($Mother1 instanceof Mother)? '是':'不是';
echo "<br>";
echo ($Mother2 instanceof Mother)? '是':'不是';
echo "<br>";
echo ($Mother1 === $Mother2) ? '完全相等':'不相等';
echo "<br>";
var_dump($Mother1,$Mother2);
?>
批改老师：韦小宝批改时间：2019-01-04 11:01:18
老师总结：写的很不错！设计模式在以后的大项目开发中使用是非常频繁的！课后一定要多练习！
