Backend Development
PHP Tutorial
Detailed explanation of usage examples of PHP namespace and automatic loading classes
Detailed explanation of usage examples of PHP namespace and automatic loading classes
This article mainly introduces PHP object-orientednamespace and automatic loading class of programming, and analyzes php namespace and automatic loading in combination with examples. The concept, function, usage and related Notes of loading classes, friends in need can refer to the following
This article describes the namespace and automatic loading classes of PHP object-oriented programming with examples. Share it with everyone for your reference, the details are as follows:
Namespace
Avoid duplication of class names and cause errors.
<?php
require_once "useful/Outputter.php";
class Outputter {
// output data
private $name;
public function setName($name) {
$this->name = $name;
}
public function getName() {
return $this->name;
}
}
$obj = new Outputter(); // 同一命名空间下,类名不能相同,默认命名空间为空。空也是一种命名空间。
$obj -> setName("Jack");
print $obj->getName();
//namespace useful; // 更改命名空间，否则查询不到Hello类,Fatal error: Class 'my\Hello' not found
$hello = new Hello();
?>
<?php
// useful/Outputter.php
namespace useful; // 命名空间
class Outputter {
//
}
class Hello {
}
?>How to call classes in the namespace
<?php
namespace com\getinstance\util;
class Debug {
static function helloWorld() {
print "hello from Debug\n";
}
}
namespace main;
// com\getinstance\util\Debug::helloWorld(); // 找不到Debug类
\com\getinstance\util\Debug::helloWorld(); // 加斜杠之后，就从根部去寻找了。
// outPut:hello from Debug
?>Use the use keyword
<?php
namespace com\getinstance\util;
class Debug {
static function helloWorld() {
print "hello from Debug\n";
}
}
namespace main;
use com\getinstance\util;
//Debug::helloWorld(); //Fatal error: Class 'main\Debug' not found
util\Debug::helloWorld();
?>Use the following Processing, you can directly call the class
<?php
namespace com\getinstance\util;
class Debug {
static function helloWorld() {
print "hello from Debug\n";
}
}
namespace main;
use com\getinstance\util\Debug; // 直接使用到类
Debug::helloWorld();
?>\ to represent the global
global.php
<?php
// no namespace
class Lister {
public static function helloWorld() {
print "hello from global\n";
}
}
?>
<?php
namespace com\getinstance\util;
require_once 'global.php';
class Lister {
public static function helloWorld() {
print "hello from ".NAMESPACE."\n"; // NAMESPACE当前namespace
}
}
Lister::helloWorld(); // access local
\Lister::helloWorld(); // access global
?>Output:
hello from com\ getinstance\util
hello from global
namespace plus {}
<?php
namespace com\getinstance\util {
class Debug {
static function helloWorld() {
print "hello from Debug\n";
}
}
}
namespace main {
\com\getinstance\util\Debug::helloWorld();
}
?>output:
hello from Debug
Global namespace
<?php
namespace { // 全局空间
class Lister {
public static function helloWorld() {
print "hello from global\n";
}
}
}
namespace com\getinstance\util {
class Lister {
public static function helloWorld() {
print "hello from ".NAMESPACE."\n";
}
}
Lister::helloWorld(); // access local
\Lister::helloWorld(); // access global
}
?>autoload automatic loading class
ShopProduct.php
<?php
class ShopProduct {
function construct() {
print "ShopProduct constructor\n";
}
}
?>
<?php
function autoload( $classname ) { // 自动加载，根据类名加载类
include_once( "$classname.php" );
}
$product = new ShopProduct( 'The Darkening', 'Harry', 'Hunter', 12.99 );
?>output:
ShopProduct constructor
Further optimization processing
is located in the folder business/ShopProduct.php
<?php
class business_ShopProduct { // 这里的类命名就要遵循规则了
function construct() {
print "business_ShopProduct constructor\n";
}
}
?>
<?php
function autoload( $classname ) {
$path = str_replace('_', DIRECTORY_SEPARATOR, $classname ); // 智能化处理
require_once( "$path.php" );
}
$x = new ShopProduct();
$y = new business_ShopProduct();
?>output:
ShopProduct constructor
business_ShopProduct constructor
The above is the detailed content of Detailed explanation of usage examples of PHP namespace and automatic loading classes. For more information, please follow other related articles on the PHP Chinese website!
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 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
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
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,
PHP Program to Count Vowels in a String
Feb 07, 2025 pm 12:12 PM
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
How do you parse and process HTML/XML in PHP?
Feb 07, 2025 am 11:57 AM
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
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.
What are PHP magic methods (__construct, __destruct, __call, __get, __set, etc.) and provide use cases?
Apr 03, 2025 am 12:03 AM
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.
PHP and Python: Comparing Two Popular Programming Languages
Apr 14, 2025 am 12:13 AM
PHP and Python each have their own advantages, and choose according to project requirements. 1.PHP is suitable for web development, especially for rapid development and maintenance of websites. 2. Python is suitable for data science, machine learning and artificial intelligence, with concise syntax and suitable for beginners.
