CS100 M Fall 2003
Review/Practice Questions for Prelim 3

Question 1

What is the output of the following program segment?

       int k, j=2, m=3;
       for (k=0; k<=m; k++)
            System.out.println("k= "+ k);
            j += 3*k;
            System.out.println("j= "+ j);

Question 2

Write a program segment that reads a non-negative integer n and outputs a triangle with n ASCII characters on each side. The n lines of the triangle alternately contains asterisks (*) and question marks (?). E.g., if the input is 5, the following pattern should be printed:

*
??
***
????
*****

Question 3

Complete Programming Project 3.18 on p.204 in Lewis and Loftus.

Question 4

Fill in the blanks to complete classes Sphere and Calculation below. Class Calculation is the client of Sphere. Read through both incomplete classes before you start writing. It may be helpful to complete class Sphere before class Calculation. Pay attention to the comments.

  public class Calculation {
     public static void main(String[] args) {
        // create two Sphere objects

	   ________________ ball =   ________________________(4.0,"ball");

	   ________________ orange = ________________________(4.0,"orange");

	// compute volume of the ball

           ________________ ballVol = ________________________;

        // print a description of the orange

           ___________________________________________________;
     } //method main
  } //class Calculation

  public class Sphere {

     ____________ double radius;      // radius of sphere

     ____________ ____________ type;  // what the sphere is

     // Constructor: assign values to the two instance variables of the Sphere

     ____________ ____________(____________ r, ____________ t) {
      ____________________________________________________________________
     |                                                                    |
     |                                                                    |
     |                                                                    |
     |____________________________________________________________________|
     } //constructor

     // instance method getVolume for calculating volume of the Sphere
      ____________________________________________________________________
     |                                                                    |
     |                                                                    |
     |                                                                    |
     |                                                                    |
     |____________________________________________________________________|

     // define a toString method for showing the type and radius of the Sphere
      ____________________________________________________________________
     |                                                                    |
     |                                                                    |
     |                                                                    |
     |                                                                    |
     |____________________________________________________________________|
  } //class Sphere