CODEWITHSUNDEEP
php
Dharman
Dharman

Reputation: 33238

What is the purpose of session_unset()?

As far as I am concerned session_unset() has no hidden features. The behavior is identical to $_SESSION = [];. Why was this function added to PHP 4? Why has it not been deprecated yet if its use is not recommended and there is no benefit to using it? Does it affect the GC in some way?

PHP C code where the function is defined: https://github.com/php/php-src/blob/master/ext/session/session.c#L2519

Upvotes: 0

Views: 96

Answers (1)

parttimeturtle
parttimeturtle

Reputation: 1215

It would matter to you if you were using a deprecated session variable, namely $HTTP_SESSION_VARS. 

Version Description
4.1.0   Introduced $_SESSION that deprecated $HTTP_SESSION_VARS.

1

session_unset() is used to clear all of the Session info $HTTP_SESSION_VARS contains without destroying the Session itself. However,

(Note that $HTTP_SESSION_VARS and $_SESSION are different variables and that PHP handles them as such)

Hence why session_unset() is useless when using the $_SESSION superglobal instead. I can't say it's that surprising that the session_unset() function is not deprecated while $HTTP_SESSION_VARS is, although I couldn't tell you exactly why that is.

Upvotes: 3

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