Question

1. Write a program in java which store 10 numbers and find the sum of odd and even numbers.
2. Create a program that uses a two dimensional array that can store integer values inside. (Just create an array with your own defined rows and columns). Make a method called Square, which gets each of the value inside the array and squares it. Make another method called ShowNumbers which shows the squared numbers.

Answer 1

Below is your code:

public class NumberArray {

        public static void main(String[] args) {
                // problem 1 to calculate sum of 10 numbers in array
                int array1[] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
                // printing array
                System.out.println("Array 1 is: ");
                for (int i = 0; i < array1.length; i++) {
                        System.out.print(array1[i] + " ");
                }
                System.out.println();
                // printing sum of array
                calculateSum(array1);
                // problem 2 to square the numbers in two dimensional array
                int array2[][] = { { 1, 2, 3, 4, 5 }, { 6, 7, 8, 9, 10 },
                                { 11, 12, 13, 14, 15 }, { 16, 17, 18, 19, 20 } };
                System.out.println("\nArray before Squaring: ");
                ShowNumbers(array2);
                array2 = Square(array2);
                System.out.println("Array After Squaring: ");
                ShowNumbers(array2);
        }

        public static void calculateSum(int array[]) {
                int sumOdd = 0;
                int sumEven = 0;
                for (int i = 0; i < array.length; i++) {
                        int num = array[i];
                        if (num % 2 == 0) {
                                sumEven = sumEven + num;
                        } else {
                                sumOdd = sumOdd + num;
                        }
                }
                System.out.println("Sum of Odd numbers: " + sumOdd);
                System.out.println("Sum of Even numbers: " + sumEven);
        }

        public static int[][] Square(int array[][]) {
                for (int i = 0; i < array.length; i++) {
                        for (int j = 0; j < array[i].length; j++) {
                                array[i][j] = array[i][j] * array[i][j];
                        }
                }
                return array;
        }

        public static void ShowNumbers(int array[][]) {
                for (int i = 0; i < array.length; i++) {
                        for (int j = 0; j < array[i].length; j++) {
                                System.out.print(array[i][j] + " ");
                        }
                        System.out.println();
                }
        }
}

Output

Array 1 is:
1 2 3 4 5 6 7 8 9 10
Sum of Odd numbers: 25
Sum of Even numbers: 30

Array before Squaring:
1 2 3 4 5
6 7 8 9 10
11 12 13 14 15
16 17 18 19 20
Array After Squaring:
1 4 9 16 25
36 49 64 81 100
121 144 169 196 225
256 289 324 361 400