session_gc

Function name: session_gc()

Applicable version: PHP 4.0.3 and above

Function description: The session_gc() function is used to manually start the session garbage collector and clear out expired session data.

Syntax: bool session_gc()

Return value: This function returns a Boolean value indicating whether the garbage collector is successfully started.

Example:

 // 启动会话垃圾回收器$result = session_gc(); if ($result) { echo "会话垃圾回收器已成功启动。"; } else { echo "会话垃圾回收器启动失败。"; }

Notes:

• By default, the session garbage collector will automatically start, clearing out expired session data. Therefore, it is usually not necessary to call the session_gc() function manually.
• The start and execution time of the session garbage collector is determined by the session.gc_probability and session.gc_divisor parameters in the php.ini configuration file. By default, the probability is 1/100, that is, only one garbage collection operation will be performed in every 100 session startups.
• The session_gc() function will only clear out expired session data and will not delete the currently used session data.