PHP stand for Hypertext Preprocessor. PHP is a Server Side Scripting Language. PHP is an Open Source Software.

On the server side: the main difference between GET and POST is where the submitted is stored. The $_GET array stores data submitted by the GET method. The $_POST array stores data submitted by the POST method.

Register the variable into the session Pass the variable as a cookie Pass the variable as part of the URL

asort() arsort() ksort() krsort() uksort() sort() rsort()

sizeof($array_variable) count($array_variable) Note: If we just pass a simple variable instead of a an array it will return 1.

The header() function sends a raw HTTP header to a client. It is important to notice that header() must be called before any actual output is sent. Example: Prevent page caching:

mysql_create_db($database_name);

include() The include() function takes all the content in a specified file and includes it in the current file. If an error occurs, the include() function generates a warning, but the script will continue execution. include_once() File will not be included more than once. If we want to include a file once only and further calling of the file will be ignored then we have to use the PHP function include_once(). require() The require() function is identical to include(), except that it handles errors differently. The require() generates a fatal error, and the script will stop. require_once() The required file is called only once when a page is open and further calling of the file will be ignored.

printf() Displays a formatted string sprintf() Saves a formatted string in a variable fprintf() Prints a formatted string to a file number_format() Formats numbers as strings

strstr() returns part of a given string from the first occurrence of a given substring to the end of the string. For example: strstr(“username@example.com”,”@”) will return “@example.com”. stristr() is idential to strstr() except that it is case insensitive.

The first one is octal 23, the second is hex 23.