Home Backend Development PHP Tutorial [PHP Learning] Six tips for using anonymous functions

[PHP Learning] Six tips for using anonymous functions

Apr 23, 2019 pm 02:12 PM
php anonymous function

This article mainly talks about six tips for using anonymous functions. It has certain learning value. Interested friends can learn it.

I have written an article about the use of closures before (click here to enter). This time I will give an in-depth summary of the in-depth usage and understanding of anonymous functions in PHP:

Anonymous functions in PHP are also called Closure functions allow specifying a function without a name. Assign the anonymous function to a variable and call it through the variable. Here is a simple example:

1

2

3

4

<?php$anonymousFunc = function($username){   

    echo $username;

  };

  $anonymousFunc("乔峰!");

Copy after login

Tip 1: Put the anonymous function in a normal function, or you can return the anonymous function. : This forms a simple closure

1

2

3

4

5

6

7

8

<?php

function closureFunc(){

    $anonymousFunc = function(){

        echo "乔峰!";

    };

    $anonymousFunc();//普通函数内部调用了匿名函数

}

closureFunc();//输出: 乔峰

Copy after login

Tip 2 Reference local variables in anonymous functions (here you need to quote a php keyword use)

1

2

3

4

5

6

7

8

9

10

<?php

 

function closureFunc(){

    $username = &#39;乔峰&#39;;

    $anonymousFunc = function() use($username){

        echo $username;

    };

    $anonymousFunc();//此处调用了匿名函数

}

closureFunc();//输出: 乔峰

Copy after login

Tip 3 Return an anonymous function in a normal function

1

2

3

4

5

6

7

8

9

10

11

<?php

 

function closureFunc(){

    $username = &#39;乔峰&#39;;

    $anonymousFunc = function() use($username){

        echo $username;

    };

    return $anonymousFunc;// 函数返回匿名函数

}

$func = closureFunc();

$func(); //然后调用$func()

Copy after login

Tip 4 Return an anonymous function and pass parameters to the anonymous function

1

2

3

4

5

6

7

8

9

10

11

<?php

 

function closureFunc(){

    $username = &#39;乔峰&#39;;

    $anonymousFunc = function($lover,$skill) use($username){

        echo $username.$lover.$skill;

    };

    return $anonymousFunc;

}

$func = closureFunc();

$func("阿朱","擒龙手");//乔峰阿朱擒龙手

Copy after login

Tips 5 Use closure to change the variable value referenced by the context

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

<?php

 

function closureFunc(){

    $number = 100;

    $anonymousFunc = function() use($number) {

        $number++;

        echo $number.PHP_EOL;

    };

    echo $number.PHP_EOL;

    return $anonymousFunc;

}

$func = closureFunc();// 这里输出1,直接调用本函数的 echo $number.PHP_EOL; 即为100

$func();// 调用函数的返回值 $anonymousFunc  $number++ 即为101

$func(); //101

$func();//101

Copy after login

Based on the above input results, it is found that the following two func() both return 101 and the value has not changed. If you want to accumulate the effect, just add An & reference symbol is enough (modifications within the anonymous function will also affect external variables), modify it:

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

<?php

 

function closureFunc(){

    $number = 100;

    $anonymousFunc = function() use(&$number) {

        $number++;

        echo $number.PHP_EOL;

    };

    echo $number.PHP_EOL;

    return $anonymousFunc;

}

$func = closureFunc();// 这里输出1,直接调用本函数的 echo $number.PHP_EOL; 即为100

$func();// 调用函数的返回值 $anonymousFunc  $number++ 即为101

$func(); //102

$func();//103

Copy after login

Tip 6 Pass the anonymous function as a parameter

1

2

3

4

5

6

7

8

9

<?php

//定义普通函数,anonymousFunc 为参数变量

function myFunc($anonymousFunc){

    $anonymousFunc("乔峰");

}

 

myFunc(function($username){ //这里调用普通函数,并把 匿名函数作为参数 传给了myFunc中的$anonymousFunc

    echo $username;

});//输出 乔峰

Copy after login

Related tutorials: PHP video tutorial

The above is the detailed content of [PHP Learning] Six tips for using anonymous functions. For more information, please follow other related articles on the PHP Chinese website!

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

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

Video Face Swap

Video Face Swap

Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Tools

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

Hot Topics

Java Tutorial
1657
14
PHP Tutorial
1257
29
C# Tutorial
1230
24
PHP 8.4 Installation and Upgrade guide for Ubuntu and Debian PHP 8.4 Installation and Upgrade guide for Ubuntu and Debian Dec 24, 2024 pm 04:42 PM

PHP 8.4 brings several new features, security improvements, and performance improvements with healthy amounts of feature deprecations and removals. This guide explains how to install PHP 8.4 or upgrade to PHP 8.4 on Ubuntu, Debian, or their derivati

How do you parse and process HTML/XML in PHP? How do you parse and process HTML/XML in PHP? Feb 07, 2025 am 11:57 AM

This tutorial demonstrates how to efficiently process XML documents using PHP. XML (eXtensible Markup Language) is a versatile text-based markup language designed for both human readability and machine parsing. It's commonly used for data storage an

Explain JSON Web Tokens (JWT) and their use case in PHP APIs. Explain JSON Web Tokens (JWT) and their use case in PHP APIs. Apr 05, 2025 am 12:04 AM

JWT is an open standard based on JSON, used to securely transmit information between parties, mainly for identity authentication and information exchange. 1. JWT consists of three parts: Header, Payload and Signature. 2. The working principle of JWT includes three steps: generating JWT, verifying JWT and parsing Payload. 3. When using JWT for authentication in PHP, JWT can be generated and verified, and user role and permission information can be included in advanced usage. 4. Common errors include signature verification failure, token expiration, and payload oversized. Debugging skills include using debugging tools and logging. 5. Performance optimization and best practices include using appropriate signature algorithms, setting validity periods reasonably,

Explain late static binding in PHP (static::). Explain late static binding in PHP (static::). Apr 03, 2025 am 12:04 AM

Static binding (static::) implements late static binding (LSB) in PHP, allowing calling classes to be referenced in static contexts rather than defining classes. 1) The parsing process is performed at runtime, 2) Look up the call class in the inheritance relationship, 3) It may bring performance overhead.

PHP Program to Count Vowels in a String PHP Program to Count Vowels in a String Feb 07, 2025 pm 12:12 PM

A string is a sequence of characters, including letters, numbers, and symbols. This tutorial will learn how to calculate the number of vowels in a given string in PHP using different methods. The vowels in English are a, e, i, o, u, and they can be uppercase or lowercase. What is a vowel? Vowels are alphabetic characters that represent a specific pronunciation. There are five vowels in English, including uppercase and lowercase: a, e, i, o, u Example 1 Input: String = "Tutorialspoint" Output: 6 explain The vowels in the string "Tutorialspoint" are u, o, i, a, o, i. There are 6 yuan in total

What are PHP magic methods (__construct, __destruct, __call, __get, __set, etc.) and provide use cases? What are PHP magic methods (__construct, __destruct, __call, __get, __set, etc.) and provide use cases? Apr 03, 2025 am 12:03 AM

What are the magic methods of PHP? PHP's magic methods include: 1.\_\_construct, used to initialize objects; 2.\_\_destruct, used to clean up resources; 3.\_\_call, handle non-existent method calls; 4.\_\_get, implement dynamic attribute access; 5.\_\_set, implement dynamic attribute settings. These methods are automatically called in certain situations, improving code flexibility and efficiency.

PHP and Python: Comparing Two Popular Programming Languages 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 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

See all articles