COP2500 Assignment 2

Deliverables: To complete this assignment you must --
1.) Write the HTML and JavaScript page described below and demonstrate to the lab instructor that it operates correctly.

Introduction: The goal of this assignment is to allow you to become familiar with converting algorithms to JavaScript and to become familiar with a few basic JavaScript commands.

Procedures:
PART 1:

  1. Open Notepad on your computer, found by clicking Start/Programs/Accessories.
  2. Using your text editor create a new document named "cop2500lab2.html". Do not close out the window until after the lab instructor has had time to verify your work.
  3. Convert the following two algorithms into JavaScript code within your HTML document. Your final web page should display the algorithm title, the input and the output. The specific format you use to display the results is up to you, but it should be clear what the input and output means (in other words, don't just list rows of numbers without words or labels describing them). The first algorithm, Fahr2Cent(), converts three temperatures given in Fahrenheit to Centigrade. The second algorithm, PriceCalc(), computes sales tax and total price for a product. Here is a brief list of helpful HTML tags and JavaScript functions.

    Fahr2Cent()
    SectionPseudocodeComments
    INPUT:Number far1, far2, far3;
    OTHER VARIABLES:Number cent1, cent2, cent3; We'll use these variables
    to store the results.
    INITIALIZATION:far1 = 32;
    far2 = 78; far3 = 212;
    Storing initial values
    for the Fahrenheit temps
    in memory.
    COMPUTATION:cent1 = 5 * (far1 - 32) / 9;
    cent2 = 5 * (far2 - 32) / 9;
    cent3 = 5 * (far3 - 32) / 9;
    Converting F - C using
    the standard formula.
    Notice how innefficient
    this repetition is -
    imagine doing 1,000,000.
    OUTPUT:return(cent1, cent2, cent3); Notice the algorithm doesn't
    say anything about format.
    You take care of that when
    You write the JavaSCript.

    PriceCalc()
    SectionPseudocodeComments
    INPUT:Number subtotal;
    OTHER VARIABLES:Number taxrate;
    Number salestax;
    Number total;
    Why do you think taxrate
    is not an input variable?
    Could it be? Should it be?
    INITIALIZATION:taxrate = 0.06;
    subtotal = 57.24;
    COMPUTATION:salestax = subtotal * taxrate;
    salestax = Math.round(salestax * 100 );
    salestax = salestax / 100;
    total = subtotal + salestax;
    If you are unsure of what the
    middle two lines are doing,
    try leaving them out and
    running the code. Math.round()
    is one of hundreds of functions
    JavaScript provides to you.
    OUTPUT:return(subtotal, total);Note we aren't returning
    the tax rate or amount of tax.
  4. Open a browser and verify that the file displays properly. Keep this window open until the instructor has had time to verify your work. In order to obtain full credit for the lab you need to email your source code to your grader, and you need to show him that it is working in the lab.