CSC 211 Spring, 2003

Sample midterm solutions

Listed below are questions similar to those I will put on the midterm. Sample solutions will be posted Thursday.

• Write a method with the header:

  public static double average(double a, double b)

  that returns the average of a and b.

  Solution:

  public static double average(double a, double b) {
    double avg = (a + b)/2;
    return avg;
  }
  

• Write a method with the header:

  public static int minimum(int i, int j)

  that returns the smaller of i and j.

  Solution:

  public static int minimum(int i, int j) {
    int min;
    if (i < j) {
      min = i;
    }
    else {
      min = j;
    }
    return min;
  }
  

• Rewrite the following mathematical expression as a Java expression: 4x³ + 16x² - 9x + 56.

  Solution: 4*Math.pow(x,3) + 16*Math.pow(x,2) - 9*x + 56.

• Write a loop that prompts the user for a month, which is an integer between 1 and 12 (inclusive).

  Solution:

  int month;
  do {
    String s = JOptionPane.showInputDialog(null, "Please enter the number of a month (1 through 12)");
    month = Integer.parseInt(s);
  } while (month < 1 || month > 12);
     

• What is printed by the following program?

  public class ExampleProgram {
      public static void main(String[] args) {
          int index = 0;
          int total = 0;
          int upper = 10;
          while (index <= upper) {
              total += index;
              index++;
          }
          System.out.println("The total is " + total);
      }
  }
      

  Solution: The program prints "The total is 55".