Cookie Concept in PHP

It is used to store application data in the client machine under a web browser. the browser contains a cookies folder by default .if we create a cookie in an application then it will automatically store information.
A cookie is used to provide variable state management options using a specific browser.
Every browser has a separate cookie folder for example if we open a chrome browser and create cookie data then it will store data under a chrome browser cookie.
A cookie is used to create remember me, bookmark option in the browser.
When we create a session then by default session data will be stored under the browser cookie.

the session will be global because it will be created by the server-side and the cookie will be local or private because it will be created by the browser and store under the browser using the local memory of the system.

Syntax of Set cookie:-
setcookie('key','value',time);
Syntax of getting cookie:-
echo $_COOKIE['key'];
when we not provide time in the set cookie then it will be automatically destroyed when the application will be closed.
If we provide time then the cookie will exist under the browser until time will complete.
create cookiepage1.php and write the following code
<?php
setcookie('cuid','aman',time()+3600);
?>
<a href="cookiepage2.php">cookiepage2 </a>
create cookiepage2.php and write the following code
.....................................................................
<?php
echo $_COOKIE['cuid'];
?>
<a href="cookiepage3.php">Cookie Page 3</a>
.................................................................................................
create cookiepage3.php and write the following code:-

<?php
setcookie('cuid','',time()-3600);  //remove cookie
?>
<a href="cookiepage2.php">cookiepage2 </a>

Another example of a cookie to create remember me?

create cookiesxample1.php with the following code:-

<?php

if(isset($_REQUEST['btnsubmit']))

{

if(isset($_REQUEST['chk']))

{

setcookie('cuid',$_REQUEST['txt'],time()+3600);

setcookie('cpass',$_REQUEST['txt1'],time()+3600);

}

}

?>

<form action="" method="post">

<input type="text" name="txt" placeholder="Enter username" />

<br><br>

<input type="password" name="txt1" placeholder="Enter password" />

<br>

<input type="checkbox" name="chk" value="1" /> Remmeber me

<br>

<input type="submit" name="btnsubmit" />

</form>

<a href="cookiepage2.php">cookiepage2 </a>

create cookiepage2.php?

<?php

echo $_COOKIE['cuid'];

echo $_COOKIE['cpass'];

?>

<a href="cookiepage3.php">Cookie Page 3</a>

create cookiepage3.php

<?php

setcookie('cuid','',time()-3600);  //remove cookie

setcookie('cpass','',time()-3600);  //remove cookie

?>

<a href="cookiepage2.php">cookiepage2 </a>