This article mainly introduces the simple implementation of thinkphp5 instance, which has certain reference value. Interested friends can refer to it
Recently learning ThinkPHP5, I saw TestClass for the first time: :instance() method can create a TestClass instance. I was very curious. I looked through the source code of ThinkPHP and generally understood its design ideas. It is very advanced.
Old rule, go directly to the code:
<?php class TestClass { public static function instance() { return new self(); } public $data = []; public function __set($name, $val) { return $this->data[$name] = $val; } public function __get($name) { return $this->data[$name]; } } $app1 = TestClass::instance(); $app1->key = 'Application 1'; echo $app1->key . '<br />'; ?>
In order to facilitate the call, I also imitated ThinkPHP and wrote an assistant function
<?php function app() { return TestClass::instance(); } $app2 = app(); $app2->key = 'Application 2'; echo $app2->key . '<br />'; ?>
This way, instance is simply implemented.
However, there is a small problem with this method. Just imagine the following. If you call it 100 times, you need to create 100 instances. It is scary to think about it.
Add a static attribute to the Test class and save the created instance here. If you need to call it next time, call this instance directly.
<?php class TestClass { public static $instance; //用于缓存实例 public $data = []; public static function instance() { //如果不存在实例,则返回实例 if (empty(self::$instance)) { self::$instance = new self(); } return self::$instance; } public function __set($name, $val) { return $this->data[$name] = $val; } public function __get($name) { return $this->data[$name]; } } function app($option = []) { return TestClass::instance($option); } header('content-type:text/plain'); $result = []; $app1 = app(); $app1->key = "Application 1"; //修改 key 为 Application 1 $result['app1'] = [ 'app1' => $app1->key, //实例中 key 为 Application 1 ]; // 创建 app2,因为 instance 已经存在实例,直接返回 缓存的实例 $app2 = app(); $result['app2'] = [ 'setp1' => [ 'app1' => $app1->key, // Application 1 'app2' => $app2->key, //因为直接调用的实例的缓存,所以 key 也是 Application 1 ], ]; // 无论 app1,app2 都对在内存中 对应的同一个实例,无论通过谁修改,都能改变值 $app1->key = "Application 2"; $result['app2']['setp2'] = [ 'app1' => $app1->key, // Application 2 'app2' => $app2->key, // Application 2 ]; print_r($result); ?>
Through the above experiment, you can see that no matter how many times it is called, the same instance will be used. This solves the problem of low efficiency.
So far, it basically satisfies most situations. The only small flaw is that the initial parameters of the instances may be different, so it cannot be called flexibly (commonly, the same program calls two databases). This can be solved by slightly modifying the above example, using the incoming parameters as keys and caching the unreasonable instances into an array.
<?php class TestClass { public static $instance = []; //用于缓存实例数组 public $data = []; public function __construct($opt = []) { $this->data = $opt; } public static function instance($option = []) { // 根据传入的参数 通过 serialize 转换为字符串,md5 后 作为数组的 key $instance_id = md5(serialize($option)); //如果 不存在实例,则创建 if (empty(self::$instance[$instance_id])) { self::$instance[$instance_id] = new self($option); } return self::$instance[$instance_id]; } public function __set($name, $val) { return $this->data[$name] = $val; } public function __get($name) { return $this->data[$name]; } } function app($option = []) { return TestClass::instance($option); } header('content-type:text/plain'); $result = []; //传入 初始数据 $app1 = app(['key' => '123']); $result['init'] = $app1->key; // 使用 传入的数据,即:123 $app1->key = "app1"; $result['app'] = $app1->key; // 现在值改为了 自定义的 app1了 print_r($result); $result = []; // 创建 app2,注意 初始参数不一样 $app2 = app(); // 因为初始参数不一样,所以还是创建新的实例 $app2->key = "app2"; $result['app1'] = $app1->key; // app1 $result['app2'] = $app2->key; // app2 print_r($result); $result = []; // 创建 app3,传入的参数 和 app1 一样,所以会直接返回 和app1相同 的 实例 $app3 = app(['key' => '123']); $result['log'] = [ 'app1' => $app1->key, // app1 'app2' => $app2->key, // app2 'app3' => $app3->key, // app1 ]; // 设置 app3 的key,会自动修改 app1 的值,因为他们两个是同一个实例 $app3->key = 'app3'; $result['app3_set'] = [ 'app1' => $app1->key, // app3 'app2' => $app2->key, // app2 'app3' => $app3->key, // app3 ]; // 同理,设置 app1 的key,app3 的 key 也会修改 $app1->key = 'app1'; $result['app1_set'] = [ 'app1' => $app1->key, // app1 'app2' => $app2->key, // app2 'app3' => $app3->key, // app1 ]; print_r($result); ?>
The above is the detailed content of A simple example of instance implementation in ThinkPhp5. For more information, please follow other related articles on the PHP Chinese website!

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 uses MySQLi and PDO extensions to interact in database operations and server-side logic processing, and processes server-side logic through functions such as session management. 1) Use MySQLi or PDO to connect to the database and execute SQL queries. 2) Handle HTTP requests and user status through session management and other functions. 3) Use transactions to ensure the atomicity of database operations. 4) Prevent SQL injection, use exception handling and closing connections for debugging. 5) Optimize performance through indexing and cache, write highly readable code and perform error handling.

Using preprocessing statements and PDO in PHP can effectively prevent SQL injection attacks. 1) Use PDO to connect to the database and set the error mode. 2) Create preprocessing statements through the prepare method and pass data using placeholders and execute methods. 3) Process query results and ensure the security and performance of the code.

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.

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 makes it easy to create interactive web content. 1) Dynamically generate content by embedding HTML and display it in real time based on user input or database data. 2) Process form submission and generate dynamic output to ensure that htmlspecialchars is used to prevent XSS. 3) Use MySQL to create a user registration system, and use password_hash and preprocessing statements to enhance security. Mastering these techniques will improve the efficiency of web development.

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 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.


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

Dreamweaver Mac version
Visual web development tools

SublimeText3 English version
Recommended: Win version, supports code prompts!

Notepad++7.3.1
Easy-to-use and free code editor

Atom editor mac version download
The most popular open source editor

SAP NetWeaver Server Adapter for Eclipse
Integrate Eclipse with SAP NetWeaver application server.