PHP中抽象类和抽象方法概念与用法分析,php抽象
PHP中抽象类和抽象方法概念与用法分析,php抽象
本文实例讲述了PHP中抽象类和抽象方法。分享给大家供大家参考,具体如下:
一、抽象关键字 :abstract
抽象就是无法确切的说明,但又有一定的概念或者名称,在PHP中声明一个抽象类或者方法我们需要使用adstract关键字。
二、抽象方法和抽象类的定义
一个类中至少有一个方法是抽象的,我们称之为抽象类。所以如果定义抽象类首先定义抽象方法。
abstract class class1{ abstract function fun1(); …… }
1、类中至少有一个抽象方法
2、抽象方法不允许有{ }
3、抽象方法前面必须要加abstract
三、抽象类和方法使用规则
抽象类的几个特点:
1、不能被实例化,只能被继承
2、继承的派生类当中要把所有抽象方法重载才能实例化
实例:
<?php abstract class cl1{ abstract function fun1(); abstract function fun2(); } class cl2 extends cl1{ function fun1(){ echo "第一个"; } function fun2(){ echo "第二个"; } } $c=new cl2(); echo $c->fun2(); ?>
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希望本文所述对大家PHP程序设计有所帮助。

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