Learning Javascript using the game VIRUS

The game VIRUS uses Javascript and standard HTML.

 

The game simulates the movement of a virus in a PC network. The task a of a player is to drop on (feed) the computers   and get away from an antivirus .

 

When the Virus eats up the computer, his body is extended and the difficulty of the game is growing. The Virus can not crash into the borders of playing area. Movement of the virus is realized by keyboard arrows.  The button New Game enables to start the new game and to set up the speed of Virus movement.  The player can continuously control the number of eated computers in time and the length of Virus.

 

When the game finishes, the player can see the total number of eated computers and time of the game.

 

 

The game can be copied and modified according to your own skills:

Right clicking the mouse will bring up a menu. The "View Source" item on the menu must be selected (the text of the menu can differ slightly according to the browser used; the text "View Source" refers to the Internet Explorer browser and the "View Page Source" is used by the Mozilla Firefox browser).

Mark the text using standard Windows OS commands (e.g. CTRL+A) and copy it into the clipboard (e.g. CTRL+C). Open any text editor capable of processing plain text (e.g. Notepad, which is part of Windows OS) and paste the text into the editor from the clipboard (e.g. CTRL+V).
Save the text displayed in the word editor as a file of any name and use either "html" or "htm" extension, which is the standard for the files to be opened in any internet browser.

Images are another essential part of the game and the list of images used is as follows:

wormy_a.gif, wormy_b.gif – pictures of a computer and an antivirus

wormy_bg.gif – background image

wormy_e.gif – end of the virus after the collision with the antivirus

wormy_hb.gif, wormy_hl.gif, wormy_hr.gif, wormy_ht.gif – the virus heads (rotation according to the movement direction)

wormy_m.gif – the virus body

wormy_tb.gif, wormy_tl.gif, wormy_tr.gif, wormy_tt.gif – the virus tails (rotation according to the movement direction)

 

The images can be downloaded via changing the address in the browser bar:   „worm.htm“  is replaced with for example „l0.gif“ .

(example www.ingot.org/javascript/cerv/worm.htm to www.ingot.org/javascript/cerv/wormy_a.gif )

After pressing "Enter" on the keyboard, a dialog box will prompt you to save a file. The file must be saved under the same name and extension and into the same directory containing the previous file. The image must be saved in the subdirectory named "images", which must be created beforehand.

Correct function of all downloaded components of the game can be verified by launching the worm.htm file.

The game images can be replaced with your own ones. The game background can be modified under the following conditions:.

-          the image files must have an identical name and extension
(more experienced programmers can use a different type of the image file, provided they modify its source code accordingly as described below.)

-          the game background is only a template, which consists of its repeated parts

-          the game background must be transparent (description of this feature is outside of the scope of this manual and can be found on the web)

-          the images must have an identical length and width measured in pixels (description of this feature is outside of the scope of this manual and can be found on the web)
 

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Brief Description of the Game Functions in JavaScript Language