search
Homephp教程php手册Abstract classes and interface definitions in PHP

Abstract class:

 1) A class containing at least one abstract method (abstract function). In other words, any class that has only one or more abstract methods is an abstract class.

 2) In an abstract class, can have concrete methods, and can have member variables.

 3) Abstract classes cannot be instantiated . They are all called abstract, so how can they be instantiated? 2333.

 4) Usage:

  abstract class Father{

protected (or public modification cannot be private, otherwise subclasses will not be able to obtain it) abstract function func1();

  }

 When implementing the inherited abstract method

  class Son extends Father{//

Like ordinary classes, a subclass can only inherit one abstract class

  public (remove abstract keyword) function func1{

    echo '

must implement all abstract methods';

   }

  }

Interface:

 1) The interfaces

are all abstract methods . (Because it is used to implement subclasses. So it must be public.)

 2) The interface

cannot have specific methods , and can only have member constants .

 3) A class

can implement multiple interfaces .

 3) Usage:

Implement multiple interfaces after the implements keyword separated by commas.

  class Son

implements InterfaceA,InterfaceB,InterfaceC {

    // 1. Implement

all abstract methods of these three interfaces, 2. Be completely consistent with the parameters of the abstract methods 3. The constants of the interface cannot be overwritten .

  }

 

Statement
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

AI Hentai Generator

AI Hentai Generator

Generate AI Hentai for free.

Hot Article

R.E.P.O. Energy Crystals Explained and What They Do (Yellow Crystal)
4 weeks agoBy尊渡假赌尊渡假赌尊渡假赌
R.E.P.O. Best Graphic Settings
4 weeks agoBy尊渡假赌尊渡假赌尊渡假赌
R.E.P.O. How to Fix Audio if You Can't Hear Anyone
4 weeks agoBy尊渡假赌尊渡假赌尊渡假赌
WWE 2K25: How To Unlock Everything In MyRise
1 months agoBy尊渡假赌尊渡假赌尊渡假赌

Hot Tools

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

MantisBT

MantisBT

Mantis is an easy-to-deploy web-based defect tracking tool designed to aid in product defect tracking. It requires PHP, MySQL and a web server. Check out our demo and hosting services.

PhpStorm Mac version

PhpStorm Mac version

The latest (2018.2.1) professional PHP integrated development tool

WebStorm Mac version

WebStorm Mac version

Useful JavaScript development tools

ZendStudio 13.5.1 Mac

ZendStudio 13.5.1 Mac

Powerful PHP integrated development environment