final static $this keyword study notes in php_PHP tutorial
In php, the final static $this keyword is mainly used in classes or objects. Now I will record my notes on learning final static $this. Friends who need to know more can refer to it.
final keyword
php final keyword is used in front of a function or class name to indicate that the function cannot be overridden or the class cannot be inherited.
1. The final method cannot be overridden.
If you do not want a method in the class to be overridden by subclasses, you only need to add the keyword final before the method, that is, set the final method.
Example:
The code is as follows | Copy code | ||||
final function fn1(){ Return "php"; } } class ex2 extends ex1{ function fn1(){ Return "html"; } } $p= new ex2(); echo $p->fn1(); ?>
|
2. Final classes cannot be inherited.
A class declared final cannot be inherited, otherwise an error will occur.
Example:
代码如下 | 复制代码 |
final class ex1{ |
The code is as follows | Copy code |
final class ex1{ |
The php static keyword can not only be used to declare a static variable, but can also declare static attributes or methods in a class, becoming "class attributes" or "class methods".
1. After declaring static attributes and methods, you cannot use the $this keyword to reference them in the class. You can use the following two methods to reference them:
In class: self::static member name
Outside the class: class name::static member name
2. When accessing this class, you do not need to instantiate it. You can directly use the format of class name::static member name.
代码如下 | 复制代码 |
|
The code is as follows | Copy code |
class user{ private static $count = 10; private static $sum=1; public function __construct(){ for($i=1;$i<11;$i++){ self::$sum = self::$sum * self::$count; /* Call static variables */ self::$count--; } } public function getCount(){ return self::$sum; } } $user1 = new user(); echo $user1->getCount(); ?> |
Static method instance:
The code is as follows
|
Copy code
return $num1 + $num2;
public static function product($num1,$num2){
echo "The sum of the two numbers is: ";
echo Math::sum($a,$b); ";
$a = 66;
$b = 88;
echo "The product of two numbers is: "; "
class user{
echo Math::product($a,$b);
class cal{ |
The code is as follows | Copy code | ||||
class user{<🎜>
private $n;<🎜>
function __construct(){<🎜>
$name="Mike";<🎜>
echo $this->n=$name;
}
}
$p=new user();
?>
2. Call method
Example:
|

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

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

If you are an experienced PHP developer, you might have the feeling that you’ve been there and done that already.You have developed a significant number of applications, debugged millions of lines of code, and tweaked a bunch of scripts to achieve op

Visual Studio Code, also known as VS Code, is a free source code editor — or integrated development environment (IDE) — available for all major operating systems. With a large collection of extensions for many programming languages, VS Code can be c

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,

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

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

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.

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.
