PHP Basics - session control - Session

1. What is? session

session Used to store user session information , The main function is to identify the current user interaction information .

session The working mechanism is : Create a unique for each visitor sessionid, Stored in cookie in Or through URL rewrite To pass .

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2. establish session

<?php
    #  establish  session  Before ,  You need to start the session first 
    session_start();

	#  establish  session
	$_SESSION['uuid'] = 'AI329D2828SD92JF01';

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3. obtain session

<?php
    if (isset($_SESSION['uuid'])) {
    
        $uuid = $_SESSION['uuid']; #  Get the name defined above as  uuid  Of  session 
    }

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4. Delete session

<?php
    #  Delete the specified  session
    if (isset($_SESSION['uuid'])) {
    
        unset($_SESSION['uuid']); #  Use  unset  To delete 
    }

	#  Delete all  session( Reset  session)
	session_destroy();

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5. Browser disable cookie after , How to use session

The first one is : adopt url Pass value

#  adopt  url  rewrite 
https://www.baidu.com?sessid=123456

The second kind : By hiding the form or ajax Pass value

<!-- html  Hide form  -->

<form name='testSID' action='/???'>
    <input type='hidden' name='sessid' value='123456'>
</form>

// ajax  Pass value ,  What we use here is  jq 
$.post("/???", {
    sessid: 123456}, function (res) {
    
});

The third kind of : modify php.ini Medium use_trans_sid

take php.ini Medium use_trans_sid=0 It is amended as follows use_trans_sid=1, It will check whether the client is disabled cookie, If you disable , By default The first one is : adopt url Pass value Way to deliver sessionid