使用了单例模式的类,有一些关于其静态成员的问题
如下单例模式的数据库类:
class Database{ static private $db; private function __construct(){ } static function getInstance(){ if(self::$db){ return self::$db; }else{ self::$db = new self(); return self::$db; } }}
有一个说法是:静态方法不能调用非静态成员。
那么这个类的定义里有这么一句:self::$db = new self();这个self()方法不就是非静态的构造函数吗?
还是“静态方法不能调用非静态成员”这个说法是不准确的?请各位前辈指教一下。
回复讨论(解决方案)
好吧,问错了,那个是实例化对象的语句,并不是调用成员的
self 和 $this 都是指类本身
只不过前者用于静态方法中,后者用于动态(实例化后的对象)方法中
new 是实例化类,构造函数不可能是静态的
注意,由于历史的原因,关闭掉 E_STRICT 级别检查,php 的类就没有静态不静态了
error_reporting(E_ALL ^ E_NOTICE ^ E_STRICT );class T { function a() { echo 'abc'; }}T::a();
这就是 php 的本原
是不是去掉那些加锁更欢快淋漓呢
self 和 $this 都是指类本身
只不过前者用于静态方法中,后者用于动态(实例化后的对象)方法中
new 是实例化类,构造函数不可能是静态的
注意,由于历史的原因,关闭掉 E_STRICT 级别检查,php 的类就没有静态不静态了
嗯,明白了,谢谢解答

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