PHP: Cookies

A cookie is a message given to a Web browser by a Web server. The browser stores the message in a small text file that the server embeds on the user's computer. Each time the same computer requests a page with a browser, the cookie is sent back to the server too.
There are a wide variety of things you can do with cookies. They are used to store information about user, visited pages, poll results and etc. The main purpose of cookies is to identify users and possibly prepare customized Web pages for them.

• How to Create a Cookie?
• How to Retrieve a Cookie Data?
• How to Delete a Cookie?

Normally cookies are used only to store small amounts of data. Websites can read the values from the cookies and use the information as desired. In addition to the information it stores, each cookie has a set of attributes that helps ensure the browser sends the correct cookie when a request to a server is made.
Even though cookies are not harmful some people do not permit cookies due to concerns about their privacy. In this case you have to use Sessions.

PHP Cookies - Explaing PHP Cookie with example

In the course of developing highly interactive web sites it is necessary to deal with large amount of data flow between client browswer and web server. It is quite cumbersome handling such large amount of data using hidden fiels in HTML forms. This problem can be overcomed by using HTTP cookies. HTTP cookies are the bunch of data/text sent by the server to the web browswer. Web browser store this data locally and send back to the server each time it accesses the server before it expires. Note that now a days Most browsers allow users choice to accept cookies or not, sometime rejection causes web site to not work properly.

setcookie() function.
This function in PHP Language is used to work with HTTP cookies. setcookie() defines a cookie to be sent along with the rest of the HTTP headers. This must be called before sending any output to the browser because cookies are part of the HTTP header. On successful it will return TRUE. But this does not mean that client browser has ccepted cookie.