详细解读PHP中接口的应用_PHP
接口
PHP类是单继承，也就是不支持多继承，当一个类需要多个类的功能时，继承就无能为力了，为此PHP引入了接口技术
如果一个抽象类里面的所有方法都是抽象方法，且没有声明变量，而且接口里面所有的成员都是public权限的，那么这种特殊的抽象类就叫接口
接口使用interface关键字定义，并使用implements来实现接口的方法，且必须完全实现
实现一个接口
下面给出PHP接口实现的一个实际例子，在此创建并实现了一个名为IPillage的接口，IPillage接口如下：
interface IPillage
{
function emptyBakAccount();
function burnDocument();
}
然后通过Executive类实现此接口：
class Executive extends Employee implements IPillage
{
private $totalStockOptions;
function emptyBankAccount()
{
echo "Call CFO and ask to transfer funds to Swiss bank account.";
}
function burnDocuments()
{
echo "Torch the office suite.";
}
}
因为公司中所有级别的人都能进行侵占，所以可以有Assistant类实现此接口：
class Assistant extends Employee implements IPillage
{
function takeMome()
{
echo "Taking memo...";
}
function emptyBankAccount()
{
echo "Go on shopping spree with office credit card.";
}
function burnDocuments()
{
echo "Start small fire in the trash can.";
}
}
可以看到，接口特别有用。因为，虽然它们定义了发生某一行为需要多少个方法，以及各个方法的名字，但接口允许不同的类，以不同的方式来实现这些方法。在这个例子中，对于烧文件的方法，Assistdnt类只是把文件在垃圾筒里烧掉，而Executive类则通过更过分的方式来做到（将它的办公室烧掉）。
实现多个接口
如果我们允许外来承包商侵占公司是不公平的，毕竟公司是在所有全职员工的努力之下建立的。就是说，怎样为员工提供工作和侵占公司的功能，而限制承包商只能完成所需的任务呢？解决的办法是将这些任务分成几项任务，然后实现必要的多个接口。PHPS 支持这个特性。考虑如下例子：
<?php
interface IEmployee{...}
interface IDeveloper{...}
interface IPillage{...}
class Employee implements IEmployee,IDeveloper,iPillage {
...
}
class Contractor implements IEmployee,IDeveloper {
...
}
?>
抽象类和接口的区别
接口是一个特殊的抽象类，也可以看作是一个模型的规范。接口与抽象类大致区别如下：
一个子类如果implements一个接口，就必须实现接口中的所有方法（不管是否需要）;如果继承一个抽象类，只需要实现需要的方法即可
如果一个接口中定义的方法名改变了，那么所有实现此接口的子类需要同步更新方法名;而抽象类中如果方法名改变了，其子类对应的方法名将不受影响，只是变成了一个新的方法而已
抽象类只能单继承，当一个子类需要实现的功能需要继承多个父类时，就必须使用接口
代码示例
<?php
/**
* 声明接口Demo
* @author wzy
*
*/
interface Demo
{
const NAME = "wangzhengyi";
const AGE = 25;
function fun1 (); // 声明方法默认是public abstract
function fun2 ();
}
/**
* 声明接口的继承Demo2
*
* @author wzy
*
*/
interface Demo2 extends Demo
{
function fun3 ();
function fun4 ();
}
/**
* 声明接口Demo3
*
* @author wzy
*
*/
interface Demo3
{
function fun5 ();
function fun6 ();
}
/**
* 声明父类ParentClass
*
* @author wzy
*
*/
class ParentClass
{
function fun7 ();
}
/**
* 子类必须实现接口中所有的方法
*
* @author wzy
*
*/
class ChildClass extends ParentClass implements Demo2, Demo3
{
function fun1 ();
function fun2 ();
function fun3 ();
function fun4 ();
function fun5 ();
function fun6 ();
}
Hot AI Tools
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Undress AI Tool
Undress images for free
Clothoff.io
AI clothes remover
Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!
Hot Article
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Hot Topics
PHP 8.4 Installation and Upgrade guide for Ubuntu and Debian
Dec 24, 2024 pm 04:42 PM
PHP 8.4 brings several new features, security improvements, and performance improvements with healthy amounts of feature deprecations and removals. This guide explains how to install PHP 8.4 or upgrade to PHP 8.4 on Ubuntu, Debian, or their derivati
7 PHP Functions I Regret I Didn't Know Before
Nov 13, 2024 am 09:42 AM
If you are an experienced PHP developer, you might have the feeling that you’ve been there and done that already.You have developed a significant number of applications, debugged millions of lines of code, and tweaked a bunch of scripts to achieve op
How To Set Up Visual Studio Code (VS Code) for PHP Development
Dec 20, 2024 am 11:31 AM
Visual Studio Code, also known as VS Code, is a free source code editor — or integrated development environment (IDE) — available for all major operating systems. With a large collection of extensions for many programming languages, VS Code can be c
Explain JSON Web Tokens (JWT) and their use case in PHP APIs.
Apr 05, 2025 am 12:04 AM
JWT is an open standard based on JSON, used to securely transmit information between parties, mainly for identity authentication and information exchange. 1. JWT consists of three parts: Header, Payload and Signature. 2. The working principle of JWT includes three steps: generating JWT, verifying JWT and parsing Payload. 3. When using JWT for authentication in PHP, JWT can be generated and verified, and user role and permission information can be included in advanced usage. 4. Common errors include signature verification failure, token expiration, and payload oversized. Debugging skills include using debugging tools and logging. 5. Performance optimization and best practices include using appropriate signature algorithms, setting validity periods reasonably,
PHP Program to Count Vowels in a String
Feb 07, 2025 pm 12:12 PM
A string is a sequence of characters, including letters, numbers, and symbols. This tutorial will learn how to calculate the number of vowels in a given string in PHP using different methods. The vowels in English are a, e, i, o, u, and they can be uppercase or lowercase. What is a vowel? Vowels are alphabetic characters that represent a specific pronunciation. There are five vowels in English, including uppercase and lowercase: a, e, i, o, u Example 1 Input: String = "Tutorialspoint" Output: 6 explain The vowels in the string "Tutorialspoint" are u, o, i, a, o, i. There are 6 yuan in total
How do you parse and process HTML/XML in PHP?
Feb 07, 2025 am 11:57 AM
This tutorial demonstrates how to efficiently process XML documents using PHP. XML (eXtensible Markup Language) is a versatile text-based markup language designed for both human readability and machine parsing. It's commonly used for data storage an
Explain late static binding in PHP (static::).
Apr 03, 2025 am 12:04 AM
Static binding (static::) implements late static binding (LSB) in PHP, allowing calling classes to be referenced in static contexts rather than defining classes. 1) The parsing process is performed at runtime, 2) Look up the call class in the inheritance relationship, 3) It may bring performance overhead.
What are PHP magic methods (__construct, __destruct, __call, __get, __set, etc.) and provide use cases?
Apr 03, 2025 am 12:03 AM
What are the magic methods of PHP? PHP's magic methods include: 1.\_\_construct, used to initialize objects; 2.\_\_destruct, used to clean up resources; 3.\_\_call, handle non-existent method calls; 4.\_\_get, implement dynamic attribute access; 5.\_\_set, implement dynamic attribute settings. These methods are automatically called in certain situations, improving code flexibility and efficiency.
