Cookies

To create and modify a cookie, use the PHP function setcookie():

setcookie('uid', 'John');

Then, you can access the value "John" of the variable uid in every further page on your site viewed by this browser. This type of cookie is called "session cookie", because it lasts for the length of a user's session.

If you want to keep the cookie after the person exits his or her browser, you must pass setcookie() through a third parameter, the date you want the cookie to expire:

<?php
$uName = 'John';
$exitDate = mktime(0,0,0,1,1,2002);
setcookie('uid', $uName, $exitDate);
?>

So the cookie will end with January 1, 2002.

If you want to update a cookie to store a newer value, you can simply overwrite its value:

<?php
$uName = 'Mike';
$exitDate = mktime(0,0,0,1,1,2002);
setcookie('uid', $uName, $exitDate);
?>

Here is the syntax for setcookie() with five arguments:

<?php
setcookie(name, value, expire, path, domain);
?>

For example:

<?php
setcookie('uid', 'John', $exitDate, '~/home', '.abc.com');
?>

It is very simple to delete a cookie: simply left the value of varible as null and just keep the name:

<?php setcookie('uid'); ?>

Note: any cookie must be set before you print any other contents:

<?php
setcookie('uid', 'John');
echo "Hello world";
?>

To get cookie value, use:

<?php
echo $_COOKIE['uid'];
?>

If you set cookie value 'John' for 'uid', then it will print 'John' on the screen.

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