Question

2. Write an exception class named InvalidTestScores. Rewrite the class written in Problem 1 to throw this new exception, InvalidTestScores, if any value in the array is an invalid number.

This is JAVA program

Answer 1

import java.util.Scanner;

class Driver {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int totalTestScores;
        try {

            System.out.println("Enter total number of Test Scores:");
            totalTestScores = sc.nextInt();
            int[] testScores = new int[totalTestScores];

            System.out.println("Please enter Test Scores:");
            for (int i = 0; i < testScores.length; i++) {
                testScores[i] = sc.nextInt();
            }
            TestScores testScoresObj = new TestScores(testScores);
            System.out.println("Average Test Score is : " + testScoresObj.averageTestScore());

        } catch (InvalidTestScores e) {
            System.out.println("Test scores must have a value less than 100 and greater than 0.");
        }
    }
}

class TestScores {

    private int testScores[];

    public TestScores(int[] testScores) throws InvalidTestScores {
        for (int i = 0; i < testScores.length; i++) {
            //If any of input value contain less than zero
            //or greater than 100 throw IllegalArgumentException
            if (testScores[i] < 0 || testScores[i] > 100) {
                throw new InvalidTestScores();
            }
        }
        //If everything went fine then assign testScores to class testScores variable
        this.testScores = testScores;
    }

    public double averageTestScore() {
        int sum = 0;
        double average;
        for (int i = 0; i < testScores.length; i++) {
            sum = sum + testScores[i];
        }
        average = (double) sum / testScores.length;
        return average;
    }
}

class InvalidTestScores extends Exception {

    public InvalidTestScores() {
    }

    public InvalidTestScores(String message) {
        super(message);
    }
}