{"id":77993,"date":"2022-09-26T01:16:57","date_gmt":"2022-09-26T01:16:57","guid":{"rendered":"https:\/\/itsourcecode.com\/?p=77993"},"modified":"2023-10-27T08:39:54","modified_gmt":"2023-10-27T08:39:54","slug":"php-session-function-start-and-destroy","status":"publish","type":"post","link":"https:\/\/itsourcecode.com\/php-tutorial\/php-session-function-start-and-destroy\/","title":{"rendered":"PHP Session Function (Start and Destroy)"},"content":{"rendered":"\n

What is a Session in PHP?<\/strong><\/h2>\n\n\n\n

PHP Sessions<\/strong> is a way to keep information from one web page to the next so that users can be recognized as they move around a site or app.<\/p>\n\n\n\n

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Do you want to know why a website needs sessions?<\/strong><\/p>\n\n\n\n

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To understand why sessions are important, we need to look at how the HTTP protocol<\/strong> is set up.<\/p>\n\n\n\n

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The HTTP protocol<\/a><\/strong> is stateless, which means that a server can’t remember a specific user between requests. <\/p>\n\n\n\n

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For instance, when you visit a website, the server’s only job is to give you the information you asked for.<\/p>\n\n\n\n

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So, when you go to other pages on the same website, the web server handles each request as if it had nothing to do with the others. <\/p>\n\n\n\n

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The server has no way of knowing that each request comes from the same user.<\/p>\n\n\n\n

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Look at the illustration below:<\/strong><\/p>\n\n\n

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\"Session<\/a><\/figure><\/div>\n\n\n

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How do you start a PHP Session?<\/strong><\/h2>\n\n\n\n

A session started with the session_start()<\/mark><\/code> function.<\/p>\n\n\n\n

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Session variables are set with the Hypertext Preprocessor<\/strong> global variable $_SESSION<\/mark><\/code>.<\/p>\n\n\n\n

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Now, let’s create a program with the file name “test_session1.php<\/strong>” to start a new session and set some session variables:<\/p>\n\n\n\n

<?php\n\/\/ Start the session\nsession_start();\n?>\n<!DOCTYPE html>\n<html>\n<body>\n\n<?php\n\/\/ Set session variables\n$_SESSION[\"name\"] = \"Angel Jude Suarez\";\n$_SESSION[\"position\"] = \"Programmer\";\necho \"Session variables are set.\";\n?>\n\n<\/body>\n<\/html><\/code><\/pre>\n\n\n\n
<\/p>\n\n\n\n
Note: The session_start()<\/mark><\/code> must be placed in the first part of the code of your php file before any HTML tags.<\/p>\n\n\n\n
<\/p>\n\n\n\n
GET the values of PHP Session variables<\/strong><\/h2>\n\n\n\n
Next, we will create another page with the file name “test_session2.php<\/strong>“. <\/p>\n\n\n\n
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From this page, we will GET the values of session variables we set on the first page with the file name “test_session1.php<\/strong>“.<\/p>\n\n\n\n
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Notice that the session variables in Hypertext Preprocessor<\/strong> are not passed individually to each new page, instead, they are retrieved from the session we open at the beginning of each page. session_start()<\/mark><\/code>.<\/p>\n\n\n\n
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Here’s the program for getting the values of session variables set on the first-page name “test_session1.php<\/strong>“.<\/p>\n\n\n\n
<?php\nsession_start();\n?>\n<!DOCTYPE html>\n<html>\n<body>\n\n<?php\n\/\/ Echo session variables that were set on previous page\necho \"Name is: \" . $_SESSION[\"name\"] . \".<br>\";\necho \"Position is: \" . $_SESSION[\"position\"] . \".\";\n?>\n\n<\/body>\n<\/html><\/code><\/pre>\n\n\n\n
<\/p>\n\n\n\n
When you execute the program this will be the output:<\/p>\n\n\n\n
Name is: Angel Jude Suarez
Position is: Programmer<\/p>\n\n\n\n
<\/p>\n\n\n\n
Destroy a PHP Session<\/strong><\/h2>\n\n\n\n
To remove all global session variables and destroy the session, we will use the session_unset()<\/mark><\/code> and session_destroy()<\/mark><\/code> functions.<\/p>\n\n\n\n
<\/p>\n\n\n\n
Here’s the program for destroying global session variables:<\/p>\n\n\n\n
<?php\nsession_start();\n?>\n<!DOCTYPE html>\n<html>\n<body>\n\n<?php\n\/\/ remove all session variables\nsession_unset();\n\n\/\/ destroy the session\nsession_destroy();\n?>\n\n<\/body>\n<\/html><\/code><\/pre>\n\n\n\n
<\/p>\n\n\n\n
Frequently Asked Questions (FAQs)<\/strong><\/h2>\n\n\n\n
What is PHP<\/strong> (Hypertext Preprocessor<\/strong>) Session and how does it work?<\/strong><\/strong> 
PHP responds by sending a unique token that identifies the current session. This is known as the session ID. In all subsequent requests, the browser sends the session ID to say, “Hello IT Source Coders.<\/strong>” All other data related to the session is stored on the web server. Only the session ID gets passed back and forth.<\/p> <\/div> 
How do you start a PHP Session?<\/strong> 
A session started with the session_start()<\/mark><\/code> function.<\/p> <\/div> 
When should I start a Session Hypertext Preprocessor<\/strong>?<\/strong> 
Before you can store any information in session variables. The session_start()<\/mark><\/code><\/mark><\/code> must be placed in the first part of the code of your php file before any HTML tag.<\/p> <\/div> <\/div>\n\n\n\n
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