国产av日韩一区二区三区精品,成人性爱视频在线观看,国产,欧美,日韩,一区,www.成色av久久成人,2222eeee成人天堂

Table of Contents
__construct() – Object Initialization
__destruct() – Cleanup After Object Is No Longer Needed
__get() and __set() – Handling Undefined Properties
__call() and __callStatic() – Handling Undefined Methods
__toString() – Custom Object String Representation
Home Backend Development PHP Tutorial What are php magic methods and list some common ones.

What are php magic methods and list some common ones.

Jul 10, 2025 am 11:55 AM

PHP magic method is a special function that is automatically triggered, used to respond to object-related events. They start with a double underscore without manual calls. 1.__construct() is used for object initialization and is automatically executed when creating an instance; 2.__destruct() performs cleaning operations when the object is destroyed; 3.__get() and __set() handle read and write undefined attributes; 4.__call() and __callStatic() handle undefined method calls; 5.__toString() defines the manifestation of the object when converting a string. These methods improve the flexibility and customizability of object behavior.

What are php magic methods and list some common ones.

PHP magic methods are special functions that get triggered automatically in response to specific events or actions involving an object. They're called "magic" because they don't need to be called directly — they run behind the scenes when certain conditions are met. These methods always start with double underscores ( __ ), and they allow developers to customize how objects behave in various situations.

What are php magic methods and list some common ones.

Here are a few commonly used magic methods in PHP:


__construct() – Object Initialization

This is probably the most widely used magic method. It's automatically called when a new instance of a class is created. You use it to set up initial values ??or perform setup tasks.

What are php magic methods and list some common ones.

Example:

 class User {
    public function __construct($name) {
        echo "User {$name} created.";
    }
}

When you do new User("Alice") , the message will show up. It's not just for printing — it's often used to inject dependencies or initialize properties.

What are php magic methods and list some common ones.

__destruct() – Cleanup After Object Is No Longer Needed

This method runs when an object is destroyed or when the script ends. It's useful for cleaning up resources like file handles, database connections, or memory.

Example:

 public function __destruct() {
    // Close a database connection or log something
}

Note: You can't pass parameters to __destruct() and it's not guaranteed to run if the script crashes or is terminated abruptly.


__get() and __set() – Handling Undefined Properties

These two methods help manage access to inaccessible or undefined properties.

  • __get($property) is called when you try to read a property that's not accessible or doesn't exist.
  • __set($property, $value) is triggered when writing to such a property.

They're useful for lazy loading or creating dynamic properties without explicitly defining them.

Example:

 class Product {
    private $data = [];

    public function __set($name, $value) {
        $this->data[$name] = $value;
    }

    public function __get($name) {
        return $this->data[$name] ?? null;
    }
}

Now you can do things like:

 $product = new Product();
$product->price = 100;
echo $product->price; // Outputs: 100

__call() and __callStatic() – Handling Undefined Methods

If you try to call a method that doesn't exist or isn't visible:

  • __call($method, $args) handles instance method calls.
  • __callStatic($method, $args) handles static method calls.

These are handy for implementing fallback logic or dynamic method handling.

Example:

 public function __call($method, $args) {
    if (strpos($method, 'get') === 0) {
        $property = lcfirst(substr($method, 3));
        return $this->$property ?? null;
    }
}

With this, calling $obj->getName() would return the value of $this->name if it exists, even if there's no explicit getName() method.


__toString() – Custom Object String Representation

This method allows an object to be treated like a string, for example when using echo $object .

You must return a string value from this method. If you return something else, PHP will throw an error.

Example:

 public function __toString() {
    return "This is a " . __CLASS__;
}

Now echo $obj; will output: This is a MyClass .


There are other magic methods too — like __invoke() , __sleep() , __wakeup() , __clone() , and more — but the ones above are the most commonly encountered in day-to-day development.

Basically that's it.

The above is the detailed content of What are php magic methods and list some common ones.. 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

Undress AI Tool

Undress AI Tool

Undress images for free

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.

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)

How do I implement authentication and authorization in PHP? How do I implement authentication and authorization in PHP? Jun 20, 2025 am 01:03 AM

TosecurelyhandleauthenticationandauthorizationinPHP,followthesesteps:1.Alwayshashpasswordswithpassword_hash()andverifyusingpassword_verify(),usepreparedstatementstopreventSQLinjection,andstoreuserdatain$_SESSIONafterlogin.2.Implementrole-basedaccessc

How can you handle file uploads securely in PHP? How can you handle file uploads securely in PHP? Jun 19, 2025 am 01:05 AM

To safely handle file uploads in PHP, the core is to verify file types, rename files, and restrict permissions. 1. Use finfo_file() to check the real MIME type, and only specific types such as image/jpeg are allowed; 2. Use uniqid() to generate random file names and store them in non-Web root directory; 3. Limit file size through php.ini and HTML forms, and set directory permissions to 0755; 4. Use ClamAV to scan malware to enhance security. These steps effectively prevent security vulnerabilities and ensure that the file upload process is safe and reliable.

What are the differences between == (loose comparison) and === (strict comparison) in PHP? What are the differences between == (loose comparison) and === (strict comparison) in PHP? Jun 19, 2025 am 01:07 AM

In PHP, the main difference between == and == is the strictness of type checking. ==Type conversion will be performed before comparison, for example, 5=="5" returns true, and ===Request that the value and type are the same before true will be returned, for example, 5==="5" returns false. In usage scenarios, === is more secure and should be used first, and == is only used when type conversion is required.

How do I perform arithmetic operations in PHP ( , -, *, /, %)? How do I perform arithmetic operations in PHP ( , -, *, /, %)? Jun 19, 2025 pm 05:13 PM

The methods of using basic mathematical operations in PHP are as follows: 1. Addition signs support integers and floating-point numbers, and can also be used for variables. String numbers will be automatically converted but not recommended to dependencies; 2. Subtraction signs use - signs, variables are the same, and type conversion is also applicable; 3. Multiplication signs use * signs, which are suitable for numbers and similar strings; 4. Division uses / signs, which need to avoid dividing by zero, and note that the result may be floating-point numbers; 5. Taking the modulus signs can be used to judge odd and even numbers, and when processing negative numbers, the remainder signs are consistent with the dividend. The key to using these operators correctly is to ensure that the data types are clear and the boundary situation is handled well.

How can you interact with NoSQL databases (e.g., MongoDB, Redis) from PHP? How can you interact with NoSQL databases (e.g., MongoDB, Redis) from PHP? Jun 19, 2025 am 01:07 AM

Yes, PHP can interact with NoSQL databases like MongoDB and Redis through specific extensions or libraries. First, use the MongoDBPHP driver (installed through PECL or Composer) to create client instances and operate databases and collections, supporting insertion, query, aggregation and other operations; second, use the Predis library or phpredis extension to connect to Redis, perform key-value settings and acquisitions, and recommend phpredis for high-performance scenarios, while Predis is convenient for rapid deployment; both are suitable for production environments and are well-documented.

How do I stay up-to-date with the latest PHP developments and best practices? How do I stay up-to-date with the latest PHP developments and best practices? Jun 23, 2025 am 12:56 AM

TostaycurrentwithPHPdevelopmentsandbestpractices,followkeynewssourceslikePHP.netandPHPWeekly,engagewithcommunitiesonforumsandconferences,keeptoolingupdatedandgraduallyadoptnewfeatures,andreadorcontributetoopensourceprojects.First,followreliablesource

What is PHP, and why is it used for web development? What is PHP, and why is it used for web development? Jun 23, 2025 am 12:55 AM

PHPbecamepopularforwebdevelopmentduetoitseaseoflearning,seamlessintegrationwithHTML,widespreadhostingsupport,andalargeecosystemincludingframeworkslikeLaravelandCMSplatformslikeWordPress.Itexcelsinhandlingformsubmissions,managingusersessions,interacti

How to set PHP time zone? How to set PHP time zone? Jun 25, 2025 am 01:00 AM

TosettherighttimezoneinPHP,usedate_default_timezone_set()functionatthestartofyourscriptwithavalididentifiersuchas'America/New_York'.1.Usedate_default_timezone_set()beforeanydate/timefunctions.2.Alternatively,configurethephp.inifilebysettingdate.timez

See all articles