search
HomeBackend DevelopmentPHP TutorialWhat are the interceptor methods in php?

What are the interceptor methods in php?

Aug 18, 2017 pm 01:25 PM
phpInterceptor

php interceptor methods include: 1. "__get" method, 2. "__set()" method; 3. "__isset()" method; 4. "__unset($property)" method; 6. "__call()" method.

What are the interceptor methods in php?

What interceptor methods does php provide?

## 1__get($property)When accessing undefined properties, call this method>= PHP 5.3.02__set($property, $value)When setting a value for an undefined property, call this method>= PHP 5.3.03__isset($property)This method is called when calling isset() on an undefined property> = PHP 5.1.04__unset($property)This method is called when unset() is called on an undefined property>= PHP 5.1.05For details, see http://php.net/manual/zh/language.oop5. Introduction to magic.php
Serial number Method name Function Implementation version
##__call($property, $args_array) When calling an undefined method, Execute this method >= PHP 5.3.0

What is a PHP interceptor?

The English name is "interceptor", its function is to intercept messages sending undefined methods and attributes.

Let’s first look at a piece of code. A School class is defined, an object $obj is instantiated, and an undefined attribute teacher is obtained. What will happen?

<?php
class School
{

}

$obj = new School;
var_dump($obj->teacher);

If you use the php command line to execute, you can see that php reported a Notice of undefined attributes, and the $obj->teacher value is a null value, so NULL

[root@localhost php]# php538 interceptor.php 
PHP Notice:  Undefined property: School::$teacher in /usr/local/sina_mobile/apache/htdocs/php/interceptor.php on line 11NULL

is printed. Let me explain here that the php command line execution and the browser page execution are not necessarily exactly the same. We can see the screenshot below. When the web server executes the same script by apache, apache reports to the browser a Notice without php, which is returned to The browser's response is 200 OK. There are problems with the interaction between php and the web server and the interaction between the web server and the browser.

1 (1).png Regarding the previous code, we think that if the teacher attribute does not exist when accessing the teacher, we can intercept the call request to the teacher and do some operations, then This is the PHP interceptor. The PHP interceptor provides a variety of methods. The __get method here is called when accessing undefined attributes.

Let’s look at the following code and results

<?php

class School
{
    function __get($var)
    {
       echo $var; echo "\r\n"; 
       return "hello";
    }

    public $name = "Tom";

}

$obj = new School;
var_dump($obj->teacher);
var_dump($obj->name);

The results of executing the following are as follows. To explain, the __get method must have a parameter, which is the undefined attribute name of the call. The function will return the result. The unknown property assigned to this call.

[root@localhost php]# php538 interceptor.php 
teacher
string(5) "hello"
string(3) "Tom"

For more related knowledge, please visit

PHP Chinese website

! !

The above is the detailed content of What are the interceptor methods in php?. For more information, please follow other related articles on the PHP Chinese website!

Statement
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
The Continued Use of PHP: Reasons for Its EnduranceThe Continued Use of PHP: Reasons for Its EnduranceApr 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.

PHP and Python: Exploring Their Similarities and DifferencesPHP and Python: Exploring Their Similarities and DifferencesApr 19, 2025 am 12:21 AM

PHP and Python are both high-level programming languages ​​that are widely used in web development, data processing and automation tasks. 1.PHP is often used to build dynamic websites and content management systems, while Python is often used to build web frameworks and data science. 2.PHP uses echo to output content, Python uses print. 3. Both support object-oriented programming, but the syntax and keywords are different. 4. PHP supports weak type conversion, while Python is more stringent. 5. PHP performance optimization includes using OPcache and asynchronous programming, while Python uses cProfile and asynchronous programming.

PHP and Python: Different Paradigms ExplainedPHP and Python: Different Paradigms ExplainedApr 18, 2025 am 12:26 AM

PHP is mainly procedural programming, but also supports object-oriented programming (OOP); Python supports a variety of paradigms, including OOP, functional and procedural programming. PHP is suitable for web development, and Python is suitable for a variety of applications such as data analysis and machine learning.

PHP and Python: A Deep Dive into Their HistoryPHP and Python: A Deep Dive into Their HistoryApr 18, 2025 am 12:25 AM

PHP originated in 1994 and was developed by RasmusLerdorf. It was originally used to track website visitors and gradually evolved into a server-side scripting language and was widely used in web development. Python was developed by Guidovan Rossum in the late 1980s and was first released in 1991. It emphasizes code readability and simplicity, and is suitable for scientific computing, data analysis and other fields.

Choosing Between PHP and Python: A GuideChoosing Between PHP and Python: A GuideApr 18, 2025 am 12:24 AM

PHP is suitable for web development and rapid prototyping, and Python is suitable for data science and machine learning. 1.PHP is used for dynamic web development, with simple syntax and suitable for rapid development. 2. Python has concise syntax, is suitable for multiple fields, and has a strong library ecosystem.

PHP and Frameworks: Modernizing the LanguagePHP and Frameworks: Modernizing the LanguageApr 18, 2025 am 12:14 AM

PHP remains important in the modernization process because it supports a large number of websites and applications and adapts to development needs through frameworks. 1.PHP7 improves performance and introduces new features. 2. Modern frameworks such as Laravel, Symfony and CodeIgniter simplify development and improve code quality. 3. Performance optimization and best practices further improve application efficiency.

PHP's Impact: Web Development and BeyondPHP's Impact: Web Development and BeyondApr 18, 2025 am 12:10 AM

PHPhassignificantlyimpactedwebdevelopmentandextendsbeyondit.1)ItpowersmajorplatformslikeWordPressandexcelsindatabaseinteractions.2)PHP'sadaptabilityallowsittoscaleforlargeapplicationsusingframeworkslikeLaravel.3)Beyondweb,PHPisusedincommand-linescrip

How does PHP type hinting work, including scalar types, return types, union types, and nullable types?How does PHP type hinting work, including scalar types, return types, union types, and nullable types?Apr 17, 2025 am 12:25 AM

PHP type prompts to improve code quality and readability. 1) Scalar type tips: Since PHP7.0, basic data types are allowed to be specified in function parameters, such as int, float, etc. 2) Return type prompt: Ensure the consistency of the function return value type. 3) Union type prompt: Since PHP8.0, multiple types are allowed to be specified in function parameters or return values. 4) Nullable type prompt: Allows to include null values ​​and handle functions that may return null values.

See all articles

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

SublimeText3 Linux new version

SublimeText3 Linux new version

SublimeText3 Linux latest version

Dreamweaver Mac version

Dreamweaver Mac version

Visual web development tools

ZendStudio 13.5.1 Mac

ZendStudio 13.5.1 Mac

Powerful PHP integrated development environment

SecLists

SecLists

SecLists is the ultimate security tester's companion. It is a collection of various types of lists that are frequently used during security assessments, all in one place. SecLists helps make security testing more efficient and productive by conveniently providing all the lists a security tester might need. List types include usernames, passwords, URLs, fuzzing payloads, sensitive data patterns, web shells, and more. The tester can simply pull this repository onto a new test machine and he will have access to every type of list he needs.

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)