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

Home Backend Development PHP Tutorial Detailed explanation of static members, abstract members, and attribute codes of php traits

Detailed explanation of static members, abstract members, and attribute codes of php traits

Jul 03, 2017 am 11:04 AM
php trait abstract

Abstract members of Trait

In order to enforce requirements on the classes used, traits support the use of abstract methods.

Indicates an example of mandatory requirements through abstract methods

<?php
trait Hello {
    public function sayHelloWorld() {
        echo &#39;Hello&#39;.$this->getWorld();
    }
    abstract public function getWorld();
}
class MyHelloWorld {
    private $world;
    use Hello;
    public function getWorld() {
        return $this->world;
    }
    public function setWorld($val) {
        $this->world = $val;
    }
}
?>

Trait's static members

Traits can be static members Static method definition.

staticExamples of variables

<?php
trait Counter {
    public function inc() {
        static $c = 0;
        $c = $c + 1;
        echo "$c\n";
    }
}
class C1 {
    use Counter;
}
class C2 {
    use Counter;
}
$o = new C1(); $o->inc(); // echo 1
$p = new C2(); $p->inc(); // echo 1
?>

Examples of static methods

<?php
trait StaticExample {
    public static function doSomething() {
        return &#39;Doing something&#39;;
    }
}
class Example {
    use StaticExample;
}
Example::doSomething();
?>

Examples of static variables and static methods

<?php
trait Counter {
    public static $c = 0;
    public static function inc() {
        self::$c = self::$c + 1;
        echo self::$c . "\n";
    }
}
class C1 {
    use Counter;
}
class C2 {
    use Counter;
}
C1::inc(); // echo 1
C2::inc(); // echo 1
?>

Attribute

Trait can also define attributes.

Example of defining attributes

<?php
trait PropertiesTrait {
    public $x = 1;
}

class PropertiesExample {
    use PropertiesTrait;
}

$example = new PropertiesExample;
$example->x;
?>

If a trait defines an attribute, the class will not be able to define an attribute with the same name, otherwise an error will be generated. If the property's definition in the class is compatible with its definition in the trait (same visibility and initial value) the error level is E_STRICT, otherwise it is a fatal error.

Conflict examples

<?php
trait PropertiesTrait {
    public $same = true;
    public $different = false;
}

class PropertiesExample {
    use PropertiesTrait;
    public $same = true; // Strict Standards
    public $different = true; // 致命錯(cuò)誤
}
?>

Differences in Use

Examples of different uses

<?php
namespace Foo\Bar;
use Foo\Test;  // means \Foo\Test - the initial \ is optional
?>
<?php
namespace Foo\Bar;
class SomeClass {
    use Foo\Test;   // means \Foo\Bar\Foo\Test
}
?>

The first use is use Foo\Test for namespace, What was found was \Foo\Test. The second use was to use a trait and what was found was \Foo\Bar\Foo\Test.

The above is the detailed content of Detailed explanation of static members, abstract members, and attribute codes of php traits. 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)

Commenting Out Code in PHP Commenting Out Code in PHP Jul 18, 2025 am 04:57 AM

There are three common methods for PHP comment code: 1. Use // or # to block one line of code, and it is recommended to use //; 2. Use /.../ to wrap code blocks with multiple lines, which cannot be nested but can be crossed; 3. Combination skills comments such as using /if(){}/ to control logic blocks, or to improve efficiency with editor shortcut keys, you should pay attention to closing symbols and avoid nesting when using them.

Tips for Writing PHP Comments Tips for Writing PHP Comments Jul 18, 2025 am 04:51 AM

The key to writing PHP comments is to clarify the purpose and specifications. Comments should explain "why" rather than "what was done", avoiding redundancy or too simplicity. 1. Use a unified format, such as docblock (/*/) for class and method descriptions to improve readability and tool compatibility; 2. Emphasize the reasons behind the logic, such as why JS jumps need to be output manually; 3. Add an overview description before complex code, describe the process in steps, and help understand the overall idea; 4. Use TODO and FIXME rationally to mark to-do items and problems to facilitate subsequent tracking and collaboration. Good annotations can reduce communication costs and improve code maintenance efficiency.

Learning PHP: A Beginner's Guide Learning PHP: A Beginner's Guide Jul 18, 2025 am 04:54 AM

TolearnPHPeffectively,startbysettingupalocalserverenvironmentusingtoolslikeXAMPPandacodeeditorlikeVSCode.1)InstallXAMPPforApache,MySQL,andPHP.2)Useacodeeditorforsyntaxsupport.3)TestyoursetupwithasimplePHPfile.Next,learnPHPbasicsincludingvariables,ech

Quick PHP Installation Tutorial Quick PHP Installation Tutorial Jul 18, 2025 am 04:52 AM

ToinstallPHPquickly,useXAMPPonWindowsorHomebrewonmacOS.1.OnWindows,downloadandinstallXAMPP,selectcomponents,startApache,andplacefilesinhtdocs.2.Alternatively,manuallyinstallPHPfromphp.netandsetupaserverlikeApache.3.OnmacOS,installHomebrew,thenrun'bre

Improving Readability with Comments Improving Readability with Comments Jul 18, 2025 am 04:46 AM

The key to writing good comments is to explain "why" rather than just "what was done" to improve the readability of the code. 1. Comments should explain logical reasons, such as considerations behind value selection or processing; 2. Use paragraph annotations for complex logic to summarize the overall idea of functions or algorithms; 3. Regularly maintain comments to ensure consistency with the code, avoid misleading, and delete outdated content if necessary; 4. Synchronously check comments when reviewing the code, and record public logic through documents to reduce the burden of code comments.

Writing Effective PHP Comments Writing Effective PHP Comments Jul 18, 2025 am 04:44 AM

Comments cannot be careless because they want to explain the reasons for the existence of the code rather than the functions, such as compatibility with old interfaces or third-party restrictions, otherwise people who read the code can only rely on guessing. The areas that must be commented include complex conditional judgments, special error handling logic, and temporary bypass restrictions. A more practical way to write comments is to select single-line comments or block comments based on the scene. Use document block comments to explain parameters and return values at the beginning of functions, classes, and files, and keep comments updated. For complex logic, you can add a line to the previous one to summarize the overall intention. At the same time, do not use comments to seal code, but use version control tools.

Mastering PHP Block Comments Mastering PHP Block Comments Jul 18, 2025 am 04:35 AM

PHPblockcommentsareusefulforwritingmulti-lineexplanations,temporarilydisablingcode,andgeneratingdocumentation.Theyshouldnotbenestedorleftunclosed.BlockcommentshelpindocumentingfunctionswithPHPDoc,whichtoolslikePhpStormuseforauto-completionanderrorche

PHP Development Environment Setup PHP Development Environment Setup Jul 18, 2025 am 04:55 AM

The first step is to select the integrated environment package XAMPP or MAMP to build a local server; the second step is to select the appropriate PHP version according to the project needs and configure multiple version switching; the third step is to select VSCode or PhpStorm as the editor and debug with Xdebug; in addition, you need to install Composer, PHP_CodeSniffer, PHPUnit and other tools to assist in development.

See all articles