Review for Second Exam

The exam will cover the lecture material from Weeks numbered 7-12 in the syllabus, as well as the labs from Weeks 7-11 (all the lectures on programming, including algorithms, javascript, how programs are processed in the CPU, limits of computation - infeasible and non-computable problems).

The parts of the textbook covered are:

• Chapters 4, 6, 10, and 11

Concepts and terms

• algorithm, program, script
• stored program concept
• how programs are executed in the CPU - roles of the ALU, Control Unit, registers, program counter, instruction register, bus
• input, output
• variables (identifiers)
• predefined functions or methods: alert, prompt
• text input boxes and buttons
• event-driven programming
• onMouseOver, onMouseOut, onClick
• properties and methods of window and document, such as document.bgColor, document.write(), window.close(), etc.
• user written functions: where are they defined; usage of the keyword function, parentheses and braces.
• loops, loops in user written functions
• infeasible problems
• computable and non-computable problems
• paradox, Halting Problem

Sample Questions

1. Short answer questions

   1. What does a compiler do?

   2. What is the purpose of a variable?

   3. What is the difference between the statements below? a) alert(number); b) alert('number');

   4. What is the difference between the statements below? a) alert("number"); b) prompt("number");

   5. What is the difference between document.bgColor and document.fgColor ?

   6. How does an image rollover work?

   7. Why is it difficult to design a computer program that will always win at playing chess?

   8. What is the Halting Problem?

   9. What is the difference between an infeasible problem and a non-computable problem?

2. Explain a web page containing Javascript

   Be prepared to look at the html for a web page and draw a picture of what gets displayed on the page, and explain what happens when buttons are pushed.

3. Write the code in Javascript

   Be prepared to write a complete Web page containing textboxes and buttons that use Javascript to accomplish a simple task:

   Examples:

   1. Write the code to display one button on the web page. The button should say "Push me". When the button is pushed, a message should appear saying "Ouch!"

   2. Write a simple script that asks for a person's name and then produces a message that says "Hello Jane" (or whatever the name is)

   3. (Similar to problem above, but uses onclick().) Write the code for a Web page that contains uses a textbox that allows the user to type in his name. The webpage also contains a button that says "Press Here". When the button is pressed, a message appears that says "Hello Jane" (or whatever the user's name is)

   4. Write a page that allows a user to enter a color and will change the background color accordingly.