1. Explain the main work/function of the following program:

 import java.util.Scanner;

 class Main {

    public static void main(String[] args) {

         char operator;

        Double number1, number2, result;

         // create an object of Scanner class

         Scanner scanner = new Scanner(System.in);

        System.out.print("Enter operator (either +, -, * or /): ");

         // ask user to enter operator

         operator = scanner.next().charAt(0);

        System.out.print("Enter number1 and number2 respectively: ");

         // ask user to enter numbers

         number1 = scanner.nextDouble();

        number2 = scanner.nextDouble();

         switch (operator) {

             // performs addition between numbers

                case '+':

                result = number1 + number2;

                System.out.print(number1 + "+" + number2 + " = " + result);

                break;

             // performs subtraction between numbers

             case '-':

                result = number1 - number2;

                System.out.print(number1 + "-" + number2 + " = " + result);

                break;

             // performs multiplication between numbers

            case '*':

                result = number1 * number2;

                System.out.print(number1 + "*" + number2 + " = " + result);

                break;

             // performs division between numbers

             case '/':

                result = number1 / number2;

                System.out.print(number1 + "/" + number2 + " = " + result);

                break;

             default:

                System.out.println("Invalid operator!");

                break;

        }

    }

}

 

 

2. Find out the output of the following code:

class Main {

    public static void main(String[] args) {

              int [] numbers = {1, 2, 3, 4, 5, 6};

        int [] positiveNumbers = numbers;    // copying arrays

         for (int number: positiveNumbers) {

            System.out.print(number + ", ");

        }

    }

}