PHP processing session function summary _ php instance

In PHP development, Session is stored on the server side, which is relatively secure and not as long as Cookie. PHP processes Session functions including: session_start, session_register, register, session_unregister, Session_destroy, etc. Here we will detail the php session processing functions, including session_start, session_register, sessions, session_unregister, and Session_destroy. I believe that you will learn more or less about the php session function when learning the php language. The following is a summary of php session function processing.

When the client's Cookie is disabled, it is automatically passed through Query_String. PHP processes a total of 10 Session functions. We will introduce several functions in detail.

PHP processes session functions 1, session_start
Function: Start a session or return an existing session.
Function prototype: boolean session_start (void );
Return Value: Boolean
Function Description: This function has no parameters and returns true. It is best to place this function first, and there cannot be any output before it, otherwise an alarm will be triggered, such as: Warning: cannot send session cache limiter-headers already sent (output started at/usr/local/apache/htdocs/cga/member/1.php: 2) in/usr/local/apache/htdocs/cga/member/1.php on line 3

PHP processes session functions 2, session_register
Function: registers a new variable as a session variable.
Function prototype: boolean session_register (string name );
Return Value: Boolean value.
Function Description: This function adds a variable to the current SESSION in the global variable. The parameter name is the name of the variable to be added. If it succeeds, the logical value true is returned. You can use $ _ SESSION [name] or $ HTTP_SESSION_VARS [name] To set values or assign values.

PHP session processing function 3, session_is_registered
Function: checks whether a variable is registered as a session variable.
Function prototype: boobean session_is_registered (string name );
Return Value: Boolean
Function Description: This function checks whether a specified variable has been registered in the current session. The parameter name is the name of the variable to be checked. If the call succeeds, the logical value true is returned.

PHP processes session functions 4, session_unregister
Function: delete a registered variable.
Function prototype: boolean session_session_unregister (string name );
Return Value: Boolean
Function Description: This function deletes the variables in the global variables in the current session. The parameter name is the name of the variable to be deleted. If it is successful, true is returned.

PHP processes session functions 5 and session_destroy
Function: ends the current session and clears all resources in the session.
Function prototype: boolean session destroy (void );
Return Value: Boolean value.
Function Description: This function ends the current session. This function has no parameters and returns true.

PHP processes session functions 6 and session_encode
Function: sesssion Information encoding
Function prototype: string session_encode (void );
Return Value: String
Function Description: The returned string contains the names and values of each variable in the global variable, in the form of a | s: 12: "it is a test"; c | s: 4: "lala"; a is the variable name s: 12 represents the value of variable a. "The length of it is a test is 12 variables separated by semicolons.

PHP processes session functions 7 and session_decode
Function: decodes sesssion information.
Function prototype: boolean session_decode (string data)
Return Value: Boolean
Function Description: This function decodes session information. If the session information is successful, the logical value true is returned.

PHP processes session functions 8 and session_name
Function: access the current session name.
Function prototype: boolean session_name (string [name]);
Return Value: String
Function Description: This function can obtain or reset the name of the current session. If the parameter name is not set, the current session name is obtained. If the parameter is added, the session name is set to the parameter name.

PHP processes session functions 9 and session_id
Function: access the ID of the current session.
Function prototype: boolean session_id (string [id]);
Return Value: String
Function Description: This function can obtain or reset the ID number of the currently stored session. If there is no parameter id, only the id of the current session is obtained. If the parameter is added, the id of the session is set to the newly specified id.

PHP processes session Functions 10 and session_unset
Function: delete all registered variables.
Function prototype: void session_unset (void)
Return Value: Boolean
Function Description: Unlike Session_destroy, this function does not end a session. Just like using the session_unregister function to cancel all session variables one by one.

The above content is the summary of PHP's session function processing. I hope you will like it.