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  • php设计模式之单例模式

    单例模式:只有一个实例,不能在new出多个,不能克隆出多个

    <?php
        class Mysql{
            //该属性用来保存实例
            private static $conn;
            //构造函数为private,防止创建对象
            private function __construct(){
                self::$conn = mysqli_connect('localhost','root','root');
            }
    
            //创建一个用来实例化对象的方法
            public static function getInstance(){
                if(!(self::$conn instanceof self)){
                    self::$conn = new self;
                }
                return self::$conn;
            }
            public static function shu(){
                echo self::$ceshi;
            }
            //防止对象被复制
            public function __clone(){
                trigger_error('Clone is not allowed !');
            }
            
        }
    
        $mysql = Mysql::getInstance();
    ?>
     
    

      参考:http://blog.csdn.net/jungsagacity/article/details/7618587

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  • 原文地址:https://www.cnblogs.com/zxqblogrecord/p/8601339.html
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