CS 140 - Homework 1 - Due Jan 23

Name:___________________________________

Answer the following questions:

1. Consider the representation for pictures described in Section 1.3 where each pixel in the picture is represented by three bytes (one for each color: red, blue, and green).
• How many bytes does it take to represent a 640x480 pictures (a common picture size)?
• How many bytes does it take to represent a 1280x1024 picture (a common desktop size)?
• Knowing this, what do you suppose is meant when a digital camera has a "5 megapixel" rating?
2. Calculate, (or try in DrJava) the following Java calls:
• What does the following statement do? System.out.println(3+2);
• What does the code below do? int x = 3; System.out.println("The result is " + x);

• What does the code below do?

  String firstName = "Sue";
System.out.println(firstName);

• What does this code do? System.out.println(3 >= 2);
3. Declare variables with reasonable types and assign them the appropriate values for the following purposes:
• Example, The price of my lunch
• double lunchPrice = 5.25;
• The number of people in your family.
• Your name.
• The temperature in the room.
• Your telephone number
• Answer to, "Are you lefthanded?"
4. What does it mean to compile a program?
5. What is a classpath?
6. Identify which of the following are class methods and which are object methods:
• Math.abs(-3);
• soundObj.play();
• FileChooser.pickAFile();
• pictureObj.show();
• ColorChooser.pickAColor();
• turtle1.turnLeft();
7. Relating to the previous question, how can you tell the difference between object and class methods?