Backend Development
PHP Tutorial
The difference between factory mode and singleton mode in PHP design patterns
The difference between factory mode and singleton mode in PHP design patterns
//让该类在外界无法造对象 //让外界可以造一个对象，做一个静态方法返回对象 //在类里面通过让静态变量控制返回对象只能是一个。
There are three main points of singleton mode:
First, a class can only have one instance;
-
The second is that it must create this instance by itself;
The third is that it must provide this instance to the entire system by itself.
Why use PHP singleton mode
1. The application of PHP is mainly in the database application. In an application There will be a large number of database operations. When developing in an object-oriented way, if you use the singleton mode, you can avoid a large number of new operations consuming resources, and you can also reduce database connections so that too many connections are less likely to occur.
2. If a class is needed to globally control certain configuration information in the system, it can be easily implemented using the singleton mode. For this, please refer to the FrontController part of the zend Framework.
3. In a page request, it is easy to debug, because all the code (such as database operation class db) is concentrated in one class, and we can set hooks in the class, Output logs to avoid var_dump and echo everywhere.
class cat
{
public $name;
private function __construct()
{
}
static $temp;
static function new_ob()
{
if(empty(self::$temp)){
self::$temp = new cat();
}
return self::$temp;
}
function speak(){
return "喵喵喵";
}
}
//$mao = new cat();
//如果没有猫就造一个，然后等于新的xxx，如果有，直接等于。达到限制的目的。
//$mao;
//if (empty($mao)){
// $mao = new cat();
//}
// $xxx = $mao;
$mao = cat::new_ob();
$mao2 = cat::new_ob();
//给1猫改名字，2猫的名字输出为1猫改的名字。此为单例。
$mao->name = "py";2. Simple factory pattern
①Abstract base class: Define some abstract methods in the class to Implement
in the subclass ② Subclass inherited from the abstract base class: Implement the abstract method in the base class
③ Factory class: Used to instantiate all corresponding subclasses
abstract class jsq
{
public $a;
public $b;
function yunsuan(){
}
}
//此为拓展
class jiafa extends jsq
{
function yunsuan()
{
//parent::yunsuan(); // TODO: Change the autogenerated stub
return $this ->a+$this->b;
}
}
class jianfa extends jsq
{
function yuansuan(){
return $this->a-$this->b;
}
}
class factory
{
static function create($x){
switch ($x){
case "+":
return new jiafa();
break;
case "-":
return new jianfa();
break;
}
}
}
//$j1 = new jiafa();
//$j1->a = 1;
//$j1->b = 2;
//$j1->yunsuan();
//尽量避免实例化对象，采用静态方法获取。
$jf = factory::create("+");
$jf->a = 1;
$jf->b = 2;
echo $jf->yunsuan();The above is the detailed content of The difference between factory mode and singleton mode in PHP design patterns. For more information, please follow other related articles on the PHP Chinese website!
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
1659
14
1415
52
1310
25
1258
29
1232
24
PHP and Python: Comparing Two Popular Programming Languages
Apr 14, 2025 am 12:13 AM
PHP and Python each have their own advantages, and choose according to project requirements. 1.PHP is suitable for web development, especially for rapid development and maintenance of websites. 2. Python is suitable for data science, machine learning and artificial intelligence, with concise syntax and suitable for beginners.
PHP: A Key Language for Web Development
Apr 13, 2025 am 12:08 AM
PHP is a scripting language widely used on the server side, especially suitable for web development. 1.PHP can embed HTML, process HTTP requests and responses, and supports a variety of databases. 2.PHP is used to generate dynamic web content, process form data, access databases, etc., with strong community support and open source resources. 3. PHP is an interpreted language, and the execution process includes lexical analysis, grammatical analysis, compilation and execution. 4.PHP can be combined with MySQL for advanced applications such as user registration systems. 5. When debugging PHP, you can use functions such as error_reporting() and var_dump(). 6. Optimize PHP code to use caching mechanisms, optimize database queries and use built-in functions. 7
PHP in Action: Real-World Examples and Applications
Apr 14, 2025 am 12:19 AM
PHP is widely used in e-commerce, content management systems and API development. 1) E-commerce: used for shopping cart function and payment processing. 2) Content management system: used for dynamic content generation and user management. 3) API development: used for RESTful API development and API security. Through performance optimization and best practices, the efficiency and maintainability of PHP applications are improved.
PHP vs. Other Languages: A Comparison
Apr 13, 2025 am 12:19 AM
PHP is suitable for web development, especially in rapid development and processing dynamic content, but is not good at data science and enterprise-level applications. Compared with Python, PHP has more advantages in web development, but is not as good as Python in the field of data science; compared with Java, PHP performs worse in enterprise-level applications, but is more flexible in web development; compared with JavaScript, PHP is more concise in back-end development, but is not as good as JavaScript in front-end development.
PHP vs. Python: Core Features and Functionality
Apr 13, 2025 am 12:16 AM
PHP and Python each have their own advantages and are suitable for different scenarios. 1.PHP is suitable for web development and provides built-in web servers and rich function libraries. 2. Python is suitable for data science and machine learning, with concise syntax and a powerful standard library. When choosing, it should be decided based on project requirements.
The Enduring Relevance of PHP: Is It Still Alive?
Apr 14, 2025 am 12:12 AM
PHP is still dynamic and still occupies an important position in the field of modern programming. 1) PHP's simplicity and powerful community support make it widely used in web development; 2) Its flexibility and stability make it outstanding in handling web forms, database operations and file processing; 3) PHP is constantly evolving and optimizing, suitable for beginners and experienced developers.
PHP's Purpose: Building Dynamic Websites
Apr 15, 2025 am 12:18 AM
PHP is used to build dynamic websites, and its core functions include: 1. Generate dynamic content and generate web pages in real time by connecting with the database; 2. Process user interaction and form submissions, verify inputs and respond to operations; 3. Manage sessions and user authentication to provide a personalized experience; 4. Optimize performance and follow best practices to improve website efficiency and security.
PHP and Python: Code Examples and Comparison
Apr 15, 2025 am 12:07 AM
PHP and Python have their own advantages and disadvantages, and the choice depends on project needs and personal preferences. 1.PHP is suitable for rapid development and maintenance of large-scale web applications. 2. Python dominates the field of data science and machine learning.
