Problem statement
a)Write a simple java program to add two integers.
b)Run the program with one positive testcase and one negative testcase.

In this program we will compute sum of two integers and display the result.

Flow Chart

Flow chart for the program depicting the steps involved.

Start
Take input two numbers a,b
Compute the sum sum = a + b
Display the sum
Terminate

 

Java Program to Add Two integers

import java.util.Scanner;

public class AddTwoNumbers {

    public static void main(String args[]) {
        Scanner input = null;
        int a,b, sum;
        try {
            input = new Scanner(System.in);
            System.out.print("Enter a:");
            a = Integer.parseInt(input.nextLine());

            System.out.print("Enter b:");
            b = Integer.parseInt(input.nextLine());

            sum = a + b ;
            System.out.print("Sum =" + sum );

        } catch(Exception e)
        {
            e.printStackTrace();
            System.out.println("Error!");
        }
        finally
        {
            if (input != null) {
                input.close();
            }
        }
    }
}

 

Run output

Positive testcase

Enter a: 25
Enter b: 50
Sum = 75

Negative testcase

Enter a: invalid input

java.lang.NumberFormatException: For input string: ” invalid input”
at java.lang.NumberFormatException.forInputString(NumberFormatException.java:65)
at java.lang.Integer.parseInt(Integer.java:569)
at java.lang.Integer.parseInt(Integer.java:615)
at com.testingdocs.simpleproject.AddTwoNumbers.main(AddTwoNumbers.java:13)
Error!