Events are user interactions with their computer, such as a mouse click or key press.
In the good ol’ days, computers handled user interactions as input of batched data. The user fed a hunk of data in, the computer did something to that data, then produced the results. With the advent of interactive devices like the GUI interface, computers could display answers to computations onscreen. The input for these interactions are events caused by the user, which could be keystrokes, button clicks, or the position of the mouse pointer.
(see Event Handler).
Practical extraction and reporting language, or Perl, is a scripting language first created by Larry Wall to be used as duct tape for programming with the Unix operating system. Due to its immense power for handling piles of text and, consequently, as a common gateway interface (CGI) scripting language, Perl became very popular among server-side scripters. Perl has a large community of contributing programmers and, what’s more, costs nothing and is free to redistribute. These circumstances have helped Perl evolve from a scripting language used to generate server stats into a language many use for database administration. All along Perl has maintained its zaniness. Most Perl documentation reads as though written by early vaudeville comedians.
x + 10
x < 10
are expressions since they can be evaluated, while
x = 10
is simply a statement
PHP is an open-source scripting language that is embedded alongside HTML to perform interactive functions, such as accessing database information. PHP is similar to Microsoft’s active server page technology, but is used primarily on Linux web servers (or Windows servers with add-on software). An HTML page that has PHP script usually has a “.php” extension. Visit Webmonkey’s Tutorial:PHP Tutorial for Beginners to learn how it works.
A function is a named group of statements in a program that performs a task when it is invoked.