 |
Cookies were invented to allow webmaster’s to store information about the user and their visit or other information on the user’s computer. Cookies are not privacy risk. All of the “trustworthy” websites use cookies.
isset — Determine whether a variable is set or not! Returns TRUE if var exists; FALSE otherwise. If a variable has been unset with unset(), it will no longer be set. isset() will return FALSE if testing a variable that has been set to NULL. isset() only works with variables as passing anything else will result in a parse error. For checking if constants are set use the defined() function.
Session support in PHP consists of a way to preserve certain data across subsequent accesses. This enables you to build more customized applications and increase the appeal of your web site. A visitor accessing your web site is assigned a unique id, the session id. This is either stored in a cookie on the user side or is propagated in the URL or can be stored in database. A normal HTML website will not pass data from one page to another. In other words, all information is forgotten when a new page is loaded. This makes it quite a problem for tasks like a shopping cart, which requires data (the user’s selected product) to be remembered from one page to the next.
