Home Backend Development PHP Tutorial Use of static methods in php object-oriented

Use of static methods in php object-oriented

Apr 11, 2017 pm 05:17 PM

What is a static method?

Not all variables and methods must be called by creating objects. You can call variables and methods directly by adding the static keyword.

The syntax format for calling static members is:

Keyword::static member

The keyword can be:

( 1) self, used when calling static members within a class.

(2) The class name where the static member is located is used when calling static members inside the class outside the class.

Note: In static methods, only static variables can be called, not ordinary variables; ordinary methods can call static variables.

Explanation of static method examples:

Static method example 1:

<?php
class Math{
static function squared($input){
return $input*$input
}
}
echo Math :: squared(3);
Copy after login

The running result is: 9

The above is a simple Instance, it is worth noting that in static methods, the $this keyword cannot be used, because there may be no object instance that can be referenced. Because static methods do not require instantiation of objects.

Using static members, in addition to eliminating the need to instantiate the object, another function is to still save the modified static data after the object is destroyed so that it can be used next time. This concept is relatively abstract. Let’s give an example to analyze it in detail.

Static method example 2:

<?php
header("content-type:text/html;charset=utf-8");
class Play{
static $num = 0;
function showNum(){
echo &#39;这是你第&#39; . self :: $num . &#39;次玩LOL&#39;;
self :: $num++ ;
}
}
$play1 = new Play();
$play1 -> showNum();
echo &#39;<br/>&#39;;
$play2 = new Play();
$play2 -> showNum();
echo &#39;<br/>&#39;;
echo &#39;这是你第&#39; . Play::$num .&#39;次玩LOL&#39;;
Copy after login

In the above example, we first defined the static variable $num, and then declared a method in the class, and called the static variable in the method. The called method You can see it in the example, and then add 1 to the static variable. Instantiate the object of the class in turn, and then call the method. Next is what we said above: after the object is destroyed, the modified static data is still saved for continued use next time.

Note:

Static methods are very easy to use. There is no need to instantiate the object. The static member space is already given when the class is loaded for the first time. But nothing can be abused. Because once too many static members are declared, the space will be occupied all the time, which will affect the running speed and functions of the system, so remember: although something is good, don’t be greedy for too much!

The above is the detailed content of Use of static methods in php object-oriented. 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

AI Hentai Generator

AI Hentai Generator

Generate AI Hentai for free.

Hot Article

R.E.P.O. Energy Crystals Explained and What They Do (Yellow Crystal)
2 weeks ago By 尊渡假赌尊渡假赌尊渡假赌
Repo: How To Revive Teammates
4 weeks ago By 尊渡假赌尊渡假赌尊渡假赌
Hello Kitty Island Adventure: How To Get Giant Seeds
3 weeks ago By 尊渡假赌尊渡假赌尊渡假赌

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)

CakePHP Project Configuration CakePHP Project Configuration Sep 10, 2024 pm 05:25 PM

In this chapter, we will understand the Environment Variables, General Configuration, Database Configuration and Email Configuration in CakePHP.

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

CakePHP Date and Time CakePHP Date and Time Sep 10, 2024 pm 05:27 PM

To work with date and time in cakephp4, we are going to make use of the available FrozenTime class.

CakePHP File upload CakePHP File upload Sep 10, 2024 pm 05:27 PM

To work on file upload we are going to use the form helper. Here, is an example for file upload.

CakePHP Routing CakePHP Routing Sep 10, 2024 pm 05:25 PM

In this chapter, we are going to learn the following topics related to routing ?

Discuss CakePHP Discuss CakePHP Sep 10, 2024 pm 05:28 PM

CakePHP is an open-source framework for PHP. It is intended to make developing, deploying and maintaining applications much easier. CakePHP is based on a MVC-like architecture that is both powerful and easy to grasp. Models, Views, and Controllers gu

How To Set Up Visual Studio Code (VS Code) for PHP Development How To Set Up Visual Studio Code (VS Code) for PHP Development Dec 20, 2024 am 11:31 AM

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

CakePHP Creating Validators CakePHP Creating Validators Sep 10, 2024 pm 05:26 PM

Validator can be created by adding the following two lines in the controller.

See all articles