There are many students and professionals in science and engineering, other than those specifically interested in fields such as computer science or computer engineering, who need to know how to solve computational problems on computers. There are b
PHP and MySQL in easy steps, 2nd edition teaches the user to write PHP server-side scr ipts and how to make MySQL database queries. It has an easy-to-follow style that will appeal to: anyone who wants to begin producing data-driven web pages. web de
但是我们知道,面向对象有三大特征:继承,多态和封装。 1. 继承 我们继续上一节中的例子,在PHP中,继承和Java是一样的,都使用extends关键字。 复制代码 代码如下: class People { private $name; public function GetName() { return $this->name; } public function SetName($name) { $this->name=$name; } } class Student exten
PHP面向对象的三大特征: 继承,封装,多态
一.继承
1、如何实现继承?
给子类使用extends关键字,让子类继承父类;
class Student extends Person{}
2、实现继承的注意事项?
① 子类只能继承父类的非私有属性。
②子类继承父类后,相当于将父类的属性和方法copy到子类,可以直接使用$this调用。
③ PHP只能单继承,不支持一个类继承多个类。但是一个类进行多层继承;
class Person{}
class Chengnian ext
本文实例讲述了php中final关键字用法。分享给大家供大家参考,具体如下:
final关键字只能用来定义类和定义方法。
使用final关键字标记的类不能被继承
final class Person{
.......
}
class Student extends Person{
.......
}
会出现错误提示。Fatal error :Class Student may not inherit from final class(Person)
使用final关键字标记的方法