


PHP variable reference Analysis of reference passing precautions for PHP function value transfer
The example in this article describes the precautions for passing by reference when passing values in PHP functions. Share it with everyone for your reference, the details are as follows:
Strict standards: Only variables should be passed by reference
I found this sentence in the online information:
This problem will occur in php5.3 and above versions, and it should be the same It is related to the configuration of PHP. As long as you split this sentence into two sentences, there will be no problem. Because the parameters of array_walk are passed by reference, only specific variables can be passed by default in version 5.3 and above, and values cannot be returned through functions. Of course you can also modify error_reporting = E_ALL | E_STRICT in php.ini, but this does not comply with the specification after all.
$suffix = array_pop(explode(".",$file_name));
Why are higher versions so restricted?
I looked at the function prototype in the manual:
mixed array_pop ( array &$array ) bool array_walk ( array &$array , callable $funcname [, mixed $userdata = NULL ] )
& symbol specifies that the variable is passed in, which is passed by reference. Just change
to:
$file_name_arr = explode(".",$file_name); $suffix = array_pop($file_name_arr);
.
Actually, it’s just a warning. Not a fatal error. Normal results can be obtained. For example, it is normal to get the suffix of the file name here.
Readers who are interested in more PHP-related content can check out the special topics of this site: "Introduction Tutorial on PHP Object-Oriented Programming", "Summary of PHP Mathematical Operation Skills", "Summary of PHP Office Document Skills (including word, excel, access) , ppt)", "Complete PHP Array (Array) Operation Skills", "PHP Data Structure and Algorithm Tutorial", "php Programming Algorithm Summary", "php Regular Expression Usage Summary", and "php Common Database Operation Skills Summary" 》
I hope this article will be helpful to everyone in PHP programming.
The above introduces the analysis of PHP variable reference and the reference passing precautions for PHP function value transfer, including the content of PHP variable reference. I hope it will be helpful to friends who are interested in PHP tutorials.

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The session realizes user authentication through the server-side state management mechanism. 1) Session creation and generation of unique IDs, 2) IDs are passed through cookies, 3) Server stores and accesses session data through IDs, 4) User authentication and status management are realized, improving application security and user experience.

Tostoreauser'snameinaPHPsession,startthesessionwithsession_start(),thenassignthenameto$_SESSION['username'].1)Usesession_start()toinitializethesession.2)Assigntheuser'snameto$_SESSION['username'].Thisallowsyoutoaccessthenameacrossmultiplepages,enhanc

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Methods to debug session problems in PHP include: 1. Check whether the session is started correctly; 2. Verify the delivery of the session ID; 3. Check the storage and reading of session data; 4. Check the server configuration. By outputting session ID and data, viewing session file content, etc., you can effectively diagnose and solve session-related problems.

Multiple calls to session_start() will result in warning messages and possible data overwrites. 1) PHP will issue a warning, prompting that the session has been started. 2) It may cause unexpected overwriting of session data. 3) Use session_status() to check the session status to avoid repeated calls.

Configuring the session lifecycle in PHP can be achieved by setting session.gc_maxlifetime and session.cookie_lifetime. 1) session.gc_maxlifetime controls the survival time of server-side session data, 2) session.cookie_lifetime controls the life cycle of client cookies. When set to 0, the cookie expires when the browser is closed.


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