Getting Data From A Request

•  How to use the build-in $_GET array.
• When an HTML <form> tags uses the GET method to pass data to a php page, the values is stored in a $_GET array. Beacause this array is a part of PHP, it is called build-in array.
• Beacause this array uses the GET method, these values is passed as a part of the URL that request the pages.
•  For example: detail.php?firstname=tien&lastname=dung.
• To retrieve values form $_GET array, you code as following:
• For example: $firstName=$_GET['firstname'].

• How to use the build-in $_POST array.
• When an HTML <form> tags uses the POST method to pass data to a php page. so passed data will be stored in $_POST array.
• The $_POST array works like $_GET array.
• So when should use the GET method and when should use the POST method.
• Using GET method:
•  when request is for a page that gets data from  a database server.
• when request can be excuted multiple times without causing any problem.
• Using POST method :
• when the request that write data to a database server.
• When excuteing the request multiple times that may cause problems.
• When you don't want to include the parameters in URL.
• When you want to transfer more than 4 KB of data.