This article introduces the abstract classes of PHP, which has certain reference value. Now I share it with you. Friends in need can refer to it
/*
The role of abstract classes:
Use it as an interface, use it as a template
To achieve polymorphism, I was born to be a father
*/
// ===Code part 1===
// =Use abstract to write an aircraft manufacturing technique= //
abstract class FlyIdea { // 大力引擎 public abstract function engine(); // 平衡舵 public abstract function balance(); /* 注意:抽象方法中 不能有方法体 下面这样写是错误的 public abstract function balance() { } 报错如下: Fatal error: Abstract function FlyIdea::balance() cannot contain body */ } /* 抽象类不能new 来实例化 $kongke = new FlyIdea(); 报错如下: Fatal error: Cannot instantiate abstract class FlyIdea */
// =Use rockets to solve engine problems= //
abstract class Rocket extends FlyIdea { public function engine() { echo '点燃火药,失去平衡。<br >'; } }class Fly extends Rocket { public function engine() { echo '用力一扔<br >'; } public function balance() { echo '两个纸翼保持平衡~~~~~~'; } public function start() { $this->engine(); for($i=0;$i<10;$i++) { $this->balance(); echo '平稳飞行<br >'; } } }$apache = new Fly();$apache->start();
/*
Summary:
Adding abstract before a class is an abstract class
Adding abstract before a method is an abstract method
Abstract classes cannot be instantiated
Abstract methods cannot have method bodies
If there is an abstract method, this class must be an abstract class
An abstract class may not have an abstract method
*/
// ===Code part 2===
// =Facebook multi-language welcome page= //
abstract class Welcome { public abstract function wel();}class china extends Welcome { public function wel() { echo '你好,非死不可<br >'; } }class english extends Welcome { public function wel() { echo 'hi,welcome<br >'; } }class japan extends Welcome { public function wel() { echo '搜达斯奈<br >'; } }$c = 'china'; //english //japan$wel = new $c();$wel->wel();
/*
Other national languages will be added in the future,
Just add a new welcome class .
*/
Related recommendations:
The difference between abstract classes and interfaces in php
The above is the detailed content of PHP abstract class. For more information, please follow other related articles on the PHP Chinese website!

php把负数转为正整数的方法:1、使用abs()函数将负数转为正数,使用intval()函数对正数取整,转为正整数,语法“intval(abs($number))”;2、利用“~”位运算符将负数取反加一,语法“~$number + 1”。

实现方法:1、使用“sleep(延迟秒数)”语句,可延迟执行函数若干秒;2、使用“time_nanosleep(延迟秒数,延迟纳秒数)”语句,可延迟执行函数若干秒和纳秒;3、使用“time_sleep_until(time()+7)”语句。

php除以100保留两位小数的方法:1、利用“/”运算符进行除法运算,语法“数值 / 100”;2、使用“number_format(除法结果, 2)”或“sprintf("%.2f",除法结果)”语句进行四舍五入的处理值,并保留两位小数。

判断方法:1、使用“strtotime("年-月-日")”语句将给定的年月日转换为时间戳格式;2、用“date("z",时间戳)+1”语句计算指定时间戳是一年的第几天。date()返回的天数是从0开始计算的,因此真实天数需要在此基础上加1。

php判断有没有小数点的方法:1、使用“strpos(数字字符串,'.')”语法,如果返回小数点在字符串中第一次出现的位置,则有小数点;2、使用“strrpos(数字字符串,'.')”语句,如果返回小数点在字符串中最后一次出现的位置,则有。

方法:1、用“str_replace(" ","其他字符",$str)”语句,可将nbsp符替换为其他字符;2、用“preg_replace("/(\s|\ \;||\xc2\xa0)/","其他字符",$str)”语句。

php字符串有下标。在PHP中,下标不仅可以应用于数组和对象,还可应用于字符串,利用字符串的下标和中括号“[]”可以访问指定索引位置的字符,并对该字符进行读写,语法“字符串名[下标值]”;字符串的下标值(索引值)只能是整数类型,起始值为0。

在PHP中,可以利用implode()函数的第一个参数来设置没有分隔符,该函数的第一个参数用于规定数组元素之间放置的内容,默认是空字符串,也可将第一个参数设置为空,语法为“implode(数组)”或者“implode("",数组)”。


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

AI Hentai Generator
Generate AI Hentai for free.

Hot Article

Hot Tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

Dreamweaver CS6
Visual web development tools

ZendStudio 13.5.1 Mac
Powerful PHP integrated development environment

Safe Exam Browser
Safe Exam Browser is a secure browser environment for taking online exams securely. This software turns any computer into a secure workstation. It controls access to any utility and prevents students from using unauthorized resources.

PhpStorm Mac version
The latest (2018.2.1) professional PHP integrated development tool
