Home Backend Development PHP Tutorial php面向对象(OOP 编程)- 类访问修饰符

php面向对象(OOP 编程)- 类访问修饰符

Jun 20, 2016 pm 12:30 PM

类型的访问修饰符允许开发人员对类成员的访问进行限制,这是PHP5的新特性


private
protected public
同一个类中
类的子类中  
所有的外部成员    

<?php/** * 类属性访问控制 * Define MyClass */class MyClass{	public $public = 'Public';	protected $protected = 'Protected';	private $private = 'Private';	function printHello()	{		echo $this->public;		echo $this->protected;		echo $this->private;	}}$obj = new MyClass();echo $obj->public;		// Worksecho $obj->protected;	// Fatal Errorecho $obj->private;		// Fatal Error$obj->printHello();		// Shows Public, Protected and Private/** * Define MyClass2 */class MyClass2 extends MyClass{	// We can redeclare the public and protected method, but not private	protected $protected = 'Protected2';	function printHello()	{		echo $this->public;		echo $this->protected;		echo $this->private;	}}$obj2 = new MyClass2();echo $obj->public;		// Worksecho $obj2->private;	// Undefinedecho $obj2->protected;	// Fatal Error$obj2->printHello();	// Shows Public, Protected2, not Private?>
Copy after login



<?php/** * 类方法访问控制 * Define MyClass */class MyClass{	// Contructors must be public	public function __construct() { }	// Declare a public method	public function MyPublic() { }	// Declare a protected method	protected function MyProtected() { }       //abstract protected function funProtect($param);抽象方法只能在抽象类中定义	// Declare a private method	private function MyPrivate() { }    	// This is public	function Foo()	{		$this->MyPublic();		$this->MyProtected();		$this->MyPrivate();	}}$myclass = new MyClass;$myclass->MyPublic();		// Works$myclass->MyProtected();	// Fatal Error$myclass->MyPrivate();		// Fatal Error$myclass->Foo();			// Public, Protected and Private work/** * Define MyClass2 */class MyClass2 extends MyClass{	// This is public	function Foo2()	{		$this->MyPublic();		$this->MyProtected();		$this->MyPrivate();		// Fatal Error	}}$myclass2 = new MyClass2;$myclass2->MyPublic();	// Works$myclass2->Foo2();		// Public and Protected work, not Private?>
Copy after login




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)

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 the concept of late static binding in PHP. Explain the concept of late static binding in PHP. Mar 21, 2025 pm 01:33 PM

Article discusses late static binding (LSB) in PHP, introduced in PHP 5.3, allowing runtime resolution of static method calls for more flexible inheritance.Main issue: LSB vs. traditional polymorphism; LSB's practical applications and potential perfo

Describe the SOLID principles and how they apply to PHP development. Describe the SOLID principles and how they apply to PHP development. Apr 03, 2025 am 12:04 AM

The application of SOLID principle in PHP development includes: 1. Single responsibility principle (SRP): Each class is responsible for only one function. 2. Open and close principle (OCP): Changes are achieved through extension rather than modification. 3. Lisch's Substitution Principle (LSP): Subclasses can replace base classes without affecting program accuracy. 4. Interface isolation principle (ISP): Use fine-grained interfaces to avoid dependencies and unused methods. 5. Dependency inversion principle (DIP): High and low-level modules rely on abstraction and are implemented through dependency injection.

How to automatically set permissions of unixsocket after system restart? How to automatically set permissions of unixsocket after system restart? Mar 31, 2025 pm 11:54 PM

How to automatically set the permissions of unixsocket after the system restarts. Every time the system restarts, we need to execute the following command to modify the permissions of unixsocket: sudo...

How does session hijacking work and how can you mitigate it in PHP? How does session hijacking work and how can you mitigate it in PHP? Apr 06, 2025 am 12:02 AM

Session hijacking can be achieved through the following steps: 1. Obtain the session ID, 2. Use the session ID, 3. Keep the session active. The methods to prevent session hijacking in PHP include: 1. Use the session_regenerate_id() function to regenerate the session ID, 2. Store session data through the database, 3. Ensure that all session data is transmitted through HTTPS.

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.

How to debug CLI mode in PHPStorm? How to debug CLI mode in PHPStorm? Apr 01, 2025 pm 02:57 PM

How to debug CLI mode in PHPStorm? When developing with PHPStorm, sometimes we need to debug PHP in command line interface (CLI) mode...

See all articles