简体中文(ZH-CN) English(EN) 繁体中文(ZH-TW) 日本語(JA) 한국어(KO) Melayu(MS) Français(FR) Deutsch(DE)
Home > Backend Development > PHP Tutorial > body text

php实现单例模式

WBOY
Release： 2016-06-23 13:24:33
Original
780 people have browsed it

<?PHPclass database{private  static $db;//设置一个静态成员变量静态方法static function getInstance(){    if(self::$db){            // 如果self::$db存在的话，不继续创建对象，直接将self::$db返回        return self::$db;    }else{            //如果self::$db 不能存在的话，直接创建对象并返回        self::$db = new database();        return self::$db;    }}}    $db = database::getInstance()；?>
Copy after login

单例模式保证系统中一个类只有一个实例并且该实例可以从外界访问

节约了系统资源，如希望在系统中某个类的对象只能存在一个，单例模式是最好的解决方案


Related labels：
php实现单例模式
source：php.cn
Previous article：php 魔术方法 sleep() wakeup() Next article：2016届360公司PHP服务端开发笔试和面试之所得所感
Statement of this Website
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
Latest Articles by Author
Latest Issues
Generate default values ​​and CSS variables using SCSS I'm implementing website styling. For legacy support reasons, I need to support IE11, at l...
From 2024-04-06 17:46:54
0
1
355
Customize the appearance of Bootstrap accordion headers using the CollapseDisplay class I want to style the card title of a panel with class collapseshow. In this example, it's t...
From 2024-04-06 12:53:11
0
1
376
JS: How to build an object based on parent properties I'm trying to create a JS object containing all URLs. I want to achieve this through the d...
From 2024-04-04 21:08:50
0
1
1411
jQuery.remove() and array.splice() issues So I have a page that has a list of items and a shopping list. If you add x number of item...
From 2024-04-04 17:21:35
0
1
347
Make sure the table cell's container fills the entire height of the parent I'm trying to vertically align the content without using Flexbox, because there are some i...
From 2024-04-04 16:03:18
0
1
404
Related Topics
More>
Popular Recommendations
Popular Tutorials
More>
Related Tutorials
Popular Recommendations
Latest courses
Latest Downloads
More>
Web Effects
Website Source Code
Website Materials
Front End Template
About us Disclaimer Sitemap
php.cn：Public welfare online PHP training，Help PHP learners grow quickly！