What are Cookies ? Using Cookies in PHP.

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This is an article on What are Cookies ? Using Cookies in PHP. in PHP.
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Cookies are basically small files which are stored in User’s Computer. Their main purpose is to hold data specific to a particular client and Website, They can only be accessed either by Web Server or the client computer. This allows the server to access user specific data while saving space on the web server, It allows the server to deliver specific tailored web pages to a particular user.

Cookies act as a mechanism to store data in the remote browser and thus tracking and identifying return users.

A Cookie mainly contains data in (key,value) pairs for example (name,aneesh) , (message,cookies are great).

That’s a lot of theory there now let’s move on how to use cookies using PHP.

Cookies in PHP



PHP provides us a with suite of functions for manipulation of cookies.

Setting of Cookies

These functions include setcookie() or setrawcookie() . As cookies are a part of HTTP headers so , it’s obvious we need to call setcookie() before sending any data.

Accessing Cookies

Any cookies which are sent to the server from the client will be automatically included in $_COOKIE auto – global array.

These cookies can be accessed using following syntax:-

Code:
   $_COOKIE['name'];
Using Cookies in PHP

The setcookie() function is used for setting of cookies

Syntax :-
Code:
  setcookie(name, value, expire, path, domain, secure, httponly);
Note: In the above all arguments except name is optional.

Example:-
Code:
  setcookie('name', 'aneesh');
This declares a cookie with name=name and value=aneesh , As no expire time is provided the cookie will be deleted from the browser after ending the session.

Example involving Expire time:-

Code:
  $minutes = 20;
  setcookie('name', 'aneesh' , time()+($minutes*60));
As the ‘expire’ time input should be in seconds we multiplied it with ‘60’ as each minute contains 60 seconds.

Printing:-
Code:
  echo $_COOKIE['name'];
This would print the value of cookie which we earlier set using setcookie()

Output:-
Code:
  aneesh

Making a Simple Application in PHP using Cookies



Now that we know quite a lot about what are cookies and how do we use them lets use them and make a small PHP Application.

Visited.php :-

Code:
  <?php
  // Header Contents
   
  $days = 10;
  $hoursPerDay = 24;
  $minutesPerHour = 60;
  $secondsPerMinute = 60;
   
  if(!isset($_COOKIE['visited']))
  {
      setcookie("visited",1,time()+($days*$hoursPerDay*$minutesPerHour*$secondsPerMinute));
  }
   
  ?>
  <html>
      <head>
          <title>
              Sample Page
          </title>
      </head>
      <h1>Welcome Visitor</h1>
      <body>
           According to your browser cookies you
           <?php
           if(isset($_COOKIE['visited']))
           {
              echo '<b>have</b>';
           }
           else
           {
              echo '<b>have not</b>';
           }
           ?>  visited our site in the last 10 days.   
      </body>
  </html>
Output :-
1. When visiting for the first time :-
Code:
  Welcome Visitor
  According to your browser cookies you have not visited our site in the last 10 days.
2. Not visiting for the first time
Code:
  Welcome Visitor
  According to your browser cookies you have visited our site in the last 10 days.
That’s all for this tutorial , Stay tuned for more
lionaneesh's Avatar, Join Date: Mar 2010
Invasive contributor
Thanks for accepting my article! and please comment what you feel!
seangtz's Avatar, Join Date: Jun 2008
Ambitious contributor
I just curious to know is there any difference between the cookies stored in web browsers and the using computers?
shabbir's Avatar, Join Date: Jul 2004
Go4Expert Founder
Quote:
Originally Posted by seangtz View Post
I just curious to know is there any difference between the cookies stored in web browsers and the using computers?
Cookies are stored in Web browser's on user's computer.
seosurendra's Avatar
Banned
Cookies is a small file but i used to data as stored in computer.
ankitasharma's Avatar
Banned
A cookie is often used to identify a user. A cookie is a small file that the server embeds on the user's computer. Each time the same computer requests a page with a browser, it will send the cookie too. With PHP, you can both create and retrieve cookie values.


How to create the cookie :-

The setcookie() function is used to set a cookie.

Note: The setcookie() function must appear BEFORE the <html> tag.

Syntax:-

setcookie(name, value, expire, path, domain);
Scripting's Avatar, Join Date: Jun 2010
John Hoder
Very useful thread !
lionaneesh's Avatar, Join Date: Mar 2010
Invasive contributor
Quote:
Originally Posted by Scripting View Post
Very useful thread !
Thanks