search
HomeBackend DevelopmentPHP TutorialPHP OOP 私有属性赋值困惑

最近发现在class 中给私有变量赋值的时候调用了函数就会报错,不得其解释,OOP方面的菜鸟,请高手解释?

class Test extends Controller {    //测试   private $test = count('csdn');}

Parse error: syntax error, unexpected '(', expecting ',' or ';'


回复讨论(解决方案)

测试写错了,是字符串长度

class Test extends Controller {    //测试   private $test = strlen('csdn');}


最近发现在class 中给私有变量赋值的时候调用了函数就会报错,不得其解释,OOP方面的菜鸟,请高手解释?

class Test extends Controller {    //测试   private $test = count('csdn');}

Parse error: syntax error, unexpected '(', expecting ',' or ';'

这并非是私有属性的原因
而是类属性在声明时不能赋予不确定的值!

define('TEST', strlen('csdn'));class Test extends Controller {    //测试   private $test = TEST;}
这样写是可以的

多谢,多谢

这并非是私有属性的原因
而是类属性在声明时不能赋予不确定的值!

受教了

define('TEST', strlen('csdn'));class Test extends Controller {    //测试   private $test = TEST;}
这样写是可以的

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
What is the difference between unset() and session_destroy()?What is the difference between unset() and session_destroy()?May 04, 2025 am 12:19 AM

Thedifferencebetweenunset()andsession_destroy()isthatunset()clearsspecificsessionvariableswhilekeepingthesessionactive,whereassession_destroy()terminatestheentiresession.1)Useunset()toremovespecificsessionvariableswithoutaffectingthesession'soveralls

What is sticky sessions (session affinity) in the context of load balancing?What is sticky sessions (session affinity) in the context of load balancing?May 04, 2025 am 12:16 AM

Stickysessionsensureuserrequestsareroutedtothesameserverforsessiondataconsistency.1)SessionIdentificationassignsuserstoserversusingcookiesorURLmodifications.2)ConsistentRoutingdirectssubsequentrequeststothesameserver.3)LoadBalancingdistributesnewuser

What are the different session save handlers available in PHP?What are the different session save handlers available in PHP?May 04, 2025 am 12:14 AM

PHPoffersvarioussessionsavehandlers:1)Files:Default,simplebutmaybottleneckonhigh-trafficsites.2)Memcached:High-performance,idealforspeed-criticalapplications.3)Redis:SimilartoMemcached,withaddedpersistence.4)Databases:Offerscontrol,usefulforintegrati

What is a session in PHP, and why are they used?What is a session in PHP, and why are they used?May 04, 2025 am 12:12 AM

Session in PHP is a mechanism for saving user data on the server side to maintain state between multiple requests. Specifically, 1) the session is started by the session_start() function, and data is stored and read through the $_SESSION super global array; 2) the session data is stored in the server's temporary files by default, but can be optimized through database or memory storage; 3) the session can be used to realize user login status tracking and shopping cart management functions; 4) Pay attention to the secure transmission and performance optimization of the session to ensure the security and efficiency of the application.

Explain the lifecycle of a PHP session.Explain the lifecycle of a PHP session.May 04, 2025 am 12:04 AM

PHPsessionsstartwithsession_start(),whichgeneratesauniqueIDandcreatesaserverfile;theypersistacrossrequestsandcanbemanuallyendedwithsession_destroy().1)Sessionsbeginwhensession_start()iscalled,creatingauniqueIDandserverfile.2)Theycontinueasdataisloade

What is the difference between absolute and idle session timeouts?What is the difference between absolute and idle session timeouts?May 03, 2025 am 12:21 AM

Absolute session timeout starts at the time of session creation, while an idle session timeout starts at the time of user's no operation. Absolute session timeout is suitable for scenarios where strict control of the session life cycle is required, such as financial applications; idle session timeout is suitable for applications that want users to keep their session active for a long time, such as social media.

What steps would you take if sessions aren't working on your server?What steps would you take if sessions aren't working on your server?May 03, 2025 am 12:19 AM

The server session failure can be solved through the following steps: 1. Check the server configuration to ensure that the session is set correctly. 2. Verify client cookies, confirm that the browser supports it and send it correctly. 3. Check session storage services, such as Redis, to ensure that they are running normally. 4. Review the application code to ensure the correct session logic. Through these steps, conversation problems can be effectively diagnosed and repaired and user experience can be improved.

What is the significance of the session_start() function?What is the significance of the session_start() function?May 03, 2025 am 12:18 AM

session_start()iscrucialinPHPformanagingusersessions.1)Itinitiatesanewsessionifnoneexists,2)resumesanexistingsession,and3)setsasessioncookieforcontinuityacrossrequests,enablingapplicationslikeuserauthenticationandpersonalizedcontent.

See all articles

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

Video Face Swap

Video Face Swap

Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

ZendStudio 13.5.1 Mac

ZendStudio 13.5.1 Mac

Powerful PHP integrated development environment

Dreamweaver Mac version

Dreamweaver Mac version

Visual web development tools

MantisBT

MantisBT

Mantis is an easy-to-deploy web-based defect tracking tool designed to aid in product defect tracking. It requires PHP, MySQL and a web server. Check out our demo and hosting services.

SAP NetWeaver Server Adapter for Eclipse

SAP NetWeaver Server Adapter for Eclipse

Integrate Eclipse with SAP NetWeaver application server.