php-Session

<Beginner PHP><Array><Loop><Function><Pre-Def variable><Session><Read Write File><CRUD>


$_SESSION

With it you can store info in variables, to be used across multiple pages
Info is not stored on the user`s computer ( <> cookies).
Session variables last until the user closes the browser
Session starts using the session_start() function 
The we set session variables with $_SESSION

<?php
session_start();
$_SESSION['color']="red";
$_SESSION['name']="John";
?>

now color and name session variables are accessible on multiple pages(until end of session)
Session start must be before any html tags.

Another page accessing session variables

<?php
session_start();
?></head><body>

<?php 
echo "your name is:".$_SESSION['name'];
?>
</body></html>

session_unset() : removes variable
session_destroy : destroy session

COOKIE

it identifies the user
it is a small file embeded in user computer
it is sent each time the page is requested
PHP creates and retrieves cookie values

Creating cookies

setcookie(name, value, expire, path, domain, secure, httponly);

  • name: required , cookie name
  • value: cookie`s value
  • expire: when the cookie expires. 86400*30 menas 30 days. If omitted default is 0 (expire on end of session)
  • path: server path of the cookie. if set to "/" then cookie available within entire domain. "/php": within php directory and sub directory. Default is current directory.
  • domain: cookie`s domain name.Example.com : available on all subdomain of example.com
  • secure: cookie transmitted over secure HTTPS connection or not. TRUE: cookie is set only if secure connection exist. Default is FALSE.
  • httponly: cookie accessible through HTTP protocol only or not. TRUE: accessible through HTTP protocol and not accessible to scripting language. Reduce identity theft using XSS attacks. Default is FALSE.

Creating Cookie code:

<?php
$ value = "John";
setcookie("user",$value,time()+(86400*30),'/');

Find out if cookie is set:


if(isset($_COOKIE['user'])){
echo "value is:".$_COOKIE['user'];
}
?>

Note: Never store sensitive data in cookies. Also respect regional regulations and user preference when using cookies, sometimes you may not use it at all.


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