Backend Development
PHP Tutorial
PHP callback function and anonymous function use case analysis
PHP callback function and anonymous function use case analysis
This time I will bring you PHP callback function and anonymous functionuse case analysis, what are the notes when using PHP callback function and anonymous function, The following is a practical case, let’s take a look.
1. Callback function
#PHP’s callback function actually has the same function as the callback function in C, Java and other languages. During the execution of the main thread, it suddenly jumps to execute the set callback function;
After the callback function is executed, it returns to the main thread to process the next process
And the callback is called in php Functions don’t want to directly use the function name as a function parameter like C and Java. Instead, use the string name corresponding to the function in PHP to execute
1.1, no-parameter callback
<?php
//无参数回调
function callback(){
echo 'execute no parameters callback.<br/>';
}
function main($callback){
echo 'execute main start.<br/>';
$callback();
echo 'execute main end.<br/>';
}
main('callback');
//结果
ecute main start.
execute no parameters callback.
execute main end.1.2, global callback Function
<?php
//全局函数回调
function callback($a,$b){
echo "$a<====>$b.<br/>";
}
$func = 'callback';
call_user_func($func, 1,2);
call_user_func_array($func, array(1,2));
//结果
1<====>2.
1<====>2.1.3, class method and static method callback
<?php
class Test{
//成员函数
function callback($a,$b){
echo "callback $a<====>$b.<br/>";
}
public static function staticCallback($a,$b){
echo "staticCallback $a<====>$b.<br/>";
}
}
//非静态方法调用方式一
$test = new Test();
call_user_func(array($test, 'callback'), 1,2);
call_user_func_array(array($test, 'callback'), array(1,2));
//非静态方法调用方式二
$func = 'callback';
$test->$func(7,9);
//静态方法调用方式
call_user_func(array('Test', 'staticCallback'), 4,6);
call_user_func_array(array('Test', 'staticCallback'), array(4,6));
call_user_func_array("Test::staticCallback", array(4,6));
//结果
callback 1<====>2.
callback 1<====>2.
callback 7<====>9.
staticCallback 4<====>6.
staticCallback 4<====>6.
staticCallback 4<====>6.2, anonymous function
2.1, in php Anonymous functions, also called closures, allow you to specify a function without a name. The most commonly used ones are callback function parametersvalue
<?php
$closureFunc = function($str){
echo $str.'<br/>';
};
$closureFunc("hello world!");
//结果
hello world!2.2, closure
2.2.1, passing in parameters and referencing local variables
<?php
$closureFunc = function($name){
$sex = '男';
$func = function($age)use ($name,$sex){
echo "$name--$sex--$age<br/>";
};
$func(23);
};
$func = $closureFunc("lvfk");
//结果
lvfk--男--232.2.2. Return closure function
<?php
$closureFunc = function($name){
echo 'closureFunc ';
$sex = '男';
echo "$name+++$sex<br/>";
$func = function()use ($name,$sex){
echo "$name--$sex<br/>";
};
return $func;
};
$func = $closureFunc("lvfk");
$func();
$func();
//结果
closureFunc lvfk+++男
lvfk--男
lvfk--男2.2.3. Closure changes the value of context, which requires reference passing
<?php
$closureFunc = function($name){
$age = 1;
echo "$name+++$age<br/>";
$func = function()use ($name,&$age){
$age++;
echo "$name--$age<br/>";
};
return $func;
};
$func = $closureFunc("lvfk");
$func();
$func();
$func();
//结果
lvfk+++1
lvfk--2
lvfk--3
lvfk--4The above is a simple application of closure , through closure, we can see that when using closure outside the function, the parameter content passed into the closure can actually be the content of the context object.
The context object value can also be changed within the closure, but it must It is passing by reference
I believe you have mastered the method after reading the case in this article. For more exciting information, please pay attention to other related articles on the PHP Chinese website!
Recommended reading:
Detailed explanation of the steps to implement one-way hash encryption in PHP
Detailed explanation of the steps to hide the entry file in PHP
The above is the detailed content of PHP callback function and anonymous function use case analysis. 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
1677
14
1431
52
1334
25
1279
29
1257
24
The Continued Use of PHP: Reasons for Its Endurance
Apr 19, 2025 am 12:23 AM
What’s still popular is the ease of use, flexibility and a strong ecosystem. 1) Ease of use and simple syntax make it the first choice for beginners. 2) Closely integrated with web development, excellent interaction with HTTP requests and database. 3) The huge ecosystem provides a wealth of tools and libraries. 4) Active community and open source nature adapts them to new needs and technology trends.
What happens if session_start() is called multiple times?
Apr 25, 2025 am 12:06 AM
Multiple calls to session_start() will result in warning messages and possible data overwrites. 1) PHP will issue a warning, prompting that the session has been started. 2) It may cause unexpected overwriting of session data. 3) Use session_status() to check the session status to avoid repeated calls.
The Compatibility of IIS and PHP: A Deep Dive
Apr 22, 2025 am 12:01 AM
IIS and PHP are compatible and are implemented through FastCGI. 1.IIS forwards the .php file request to the FastCGI module through the configuration file. 2. The FastCGI module starts the PHP process to process requests to improve performance and stability. 3. In actual applications, you need to pay attention to configuration details, error debugging and performance optimization.
What is the significance of the session_start() function?
May 03, 2025 am 12:18 AM
session_start()iscrucialinPHPformanagingusersessions.1)Itinitiatesanewsessionifnoneexists,2)resumesanexistingsession,and3)setsasessioncookieforcontinuityacrossrequests,enablingapplicationslikeuserauthenticationandpersonalizedcontent.
Composer: Aiding PHP Development Through AI
Apr 29, 2025 am 12:27 AM
AI can help optimize the use of Composer. Specific methods include: 1. Dependency management optimization: AI analyzes dependencies, recommends the best version combination, and reduces conflicts. 2. Automated code generation: AI generates composer.json files that conform to best practices. 3. Improve code quality: AI detects potential problems, provides optimization suggestions, and improves code quality. These methods are implemented through machine learning and natural language processing technologies to help developers improve efficiency and code quality.
Using Laravel: Streamlining Web Development with PHP
Apr 19, 2025 am 12:18 AM
Laravel optimizes the web development process including: 1. Use the routing system to manage the URL structure; 2. Use the Blade template engine to simplify view development; 3. Handle time-consuming tasks through queues; 4. Use EloquentORM to simplify database operations; 5. Follow best practices to improve code quality and maintainability.
PHP and IIS: Making Them Work Together
Apr 21, 2025 am 12:06 AM
Configuring and running PHP on IIS requires the following steps: 1) Download and install PHP, 2) Configuring IIS and adding FastCGI module, 3) Create and set up an application pool, 4) Create a website and bind to an application pool. Through these steps, you can easily deploy PHP applications on your Windows server and improve application stability and efficiency by configuring scaling and optimizing performance.
H5: Key Improvements in HTML5
Apr 28, 2025 am 12:26 AM
HTML5 brings five key improvements: 1. Semantic tags improve code clarity and SEO effects; 2. Multimedia support simplifies video and audio embedding; 3. Form enhancement simplifies verification; 4. Offline and local storage improves user experience; 5. Canvas and graphics functions enhance the visualization of web pages.
