The following is a list of some of the PHP functions and constants used:
__CLASS__:PHP constant that contains the name of the PHP class in which it appears.
__FILE__:PHP constant that contains the name of the file in which appears.
parent::__construct():A convenient way to run the
__constructin the parent class. This statement is only used in a child class.
trim():Removes whitespace from the beginning and end of a string.
rand(x,y):Picks a random number between x and y.
explode($separator, $str):Separates a string
$strinto an array by splitting it at each instance of
stripslashes():Removes backslashes from form-submitted data.