What Do These PHP Symbols Mean?-PHP Tutorial-php.cn

Home

Backend Development

PHP Tutorial

What Do These PHP Symbols Mean?

Linda Hamilton

Dec 24, 2024 am 02:22 AM

What Do These PHP Symbols Mean?

What does this symbol mean in PHP?

This document provides a comprehensive list of frequently asked questions and corresponding Stack Overflow links about various symbols, operators, and syntax elements in PHP. It serves as a reference guide to help developers quickly understand the meaning and usage of these symbols.

PHP Syntax:

&: Bitwise Operators or References
=&: References
&=: Bitwise Operators
&&: Logical Operators
%: Arithmetic Operators
!!: Logical Operators
@: Error Control Operators
?:: Ternary Operator
??: Null Coalesce Operator (since PHP 7)
?string: Nullable type declaration (since PHP 7.1)
?->: NullSafe Operator (since PHP 8.0)
:: Alternative syntax for control structures, Ternary Operator, Return Type Declaration
::: Scope Resolution Operator
: Namespaces
->: Classes And Objects
=>: Arrays
^: Bitwise Operators
>>: Bitwise Operators
=: Assignment Operators
==: Comparison Operators
===: Comparison Operators
!==: Comparison Operators
!=: Comparison Operators
: Comparison Operators
: Comparison Operators (since PHP 7.0)
|: Bitwise Operators
||: Logical Operators
~: Bitwise Operators
: Arithmetic Operators, Array Operators
= and -=: Assignment Operators
and --: Incrementing/Decrementing Operators
.=: Assignment Operators
.: String Operators
,: Function Arguments, Variable Declarations
$$: Variable Variables
': Execution Operator
=: Short Open Tags
[]: Arrays (short syntax since PHP 5.4)
..: Double-dot character range
...: Argument unpacking (since PHP 5.6)
'**`: Exponentiation (since PHP 5.6)
#: One-line shell-style comment
#[]: Attributes (since PHP 8)

Please refer to the corresponding Stack Overflow links for detailed explanations and examples.

The above is the detailed content of What Do These PHP Symbols Mean?. For more information, please follow other related articles on the PHP Chinese website!

Statement

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

PHP Performance Tuning for High Traffic WebsitesMay 14, 2025 am 12:13 AM

ThesecrettokeepingaPHP-poweredwebsiterunningsmoothlyunderheavyloadinvolvesseveralkeystrategies:1)ImplementopcodecachingwithOPcachetoreducescriptexecutiontime,2)UsedatabasequerycachingwithRedistolessendatabaseload,3)LeverageCDNslikeCloudflareforservin

Dependency Injection in PHP: Code Examples for BeginnersMay 14, 2025 am 12:08 AM

You should care about DependencyInjection(DI) because it makes your code clearer and easier to maintain. 1) DI makes it more modular by decoupling classes, 2) improves the convenience of testing and code flexibility, 3) Use DI containers to manage complex dependencies, but pay attention to performance impact and circular dependencies, 4) The best practice is to rely on abstract interfaces to achieve loose coupling.

PHP Performance: is it possible to optimize the application?May 14, 2025 am 12:04 AM

Yes,optimizingaPHPapplicationispossibleandessential.1)ImplementcachingusingAPCutoreducedatabaseload.2)Optimizedatabaseswithindexing,efficientqueries,andconnectionpooling.3)Enhancecodewithbuilt-infunctions,avoidingglobalvariables,andusingopcodecaching

PHP Performance Optimization: The Ultimate GuideMay 14, 2025 am 12:02 AM

ThekeystrategiestosignificantlyboostPHPapplicationperformanceare:1)UseopcodecachinglikeOPcachetoreduceexecutiontime,2)Optimizedatabaseinteractionswithpreparedstatementsandproperindexing,3)ConfigurewebserverslikeNginxwithPHP-FPMforbetterperformance,4)

PHP Dependency Injection Container: A Quick StartMay 13, 2025 am 12:11 AM

APHPDependencyInjectionContainerisatoolthatmanagesclassdependencies,enhancingcodemodularity,testability,andmaintainability.Itactsasacentralhubforcreatingandinjectingdependencies,thusreducingtightcouplingandeasingunittesting.

Dependency Injection vs. Service Locator in PHPMay 13, 2025 am 12:10 AM

Select DependencyInjection (DI) for large applications, ServiceLocator is suitable for small projects or prototypes. 1) DI improves the testability and modularity of the code through constructor injection. 2) ServiceLocator obtains services through center registration, which is convenient but may lead to an increase in code coupling.

PHP performance optimization strategies.May 13, 2025 am 12:06 AM

PHPapplicationscanbeoptimizedforspeedandefficiencyby:1)enablingopcacheinphp.ini,2)usingpreparedstatementswithPDOfordatabasequeries,3)replacingloopswitharray_filterandarray_mapfordataprocessing,4)configuringNginxasareverseproxy,5)implementingcachingwi

PHP Email Validation: Ensuring Emails Are Sent CorrectlyMay 13, 2025 am 12:06 AM

PHPemailvalidationinvolvesthreesteps:1)Formatvalidationusingregularexpressionstochecktheemailformat;2)DNSvalidationtoensurethedomainhasavalidMXrecord;3)SMTPvalidation,themostthoroughmethod,whichchecksifthemailboxexistsbyconnectingtotheSMTPserver.Impl

See all articles