Question

JAVA

Ask the user for integers. If the user did not enter an integer, ask again. (Type Safe Input) Keep a running total of the intergers entered (sum). Once the user enters 0, stop looping. Print the sum of all the numbers. Do not use try-catch.

EXAMPLE OUTPUT:

Enter an integer, 0 to stop> [fasdfsa]

Invalid input.

Enter an integer, 0 to stop> [231.342]

Invalid input.

Enter an integer, 0 to stop> [1]

Enter an integer, 0 to stop> [2]

Enter an integer, 0 to stop> [3]

Enter an integer, 0 to stop> [0]

The sum is: 6

Answer 1

import java.util.Scanner;

public class ValidIntegers {
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        int n = 1, sum = 0;
        String s;
        boolean f;

        while (n!=0) {
            System.out.print("Enter an integer, 0 to stop> ");
            s = scan.nextLine();

            f = false;
            for(int i = 0;i<s.length();i++){
                if(!(s.charAt(i)>='0' && s.charAt(i)<='9')){
                    f = true;
                }
            }
            if(f){
                System.out.println("Invalid input.");
            }
            else {
                n = Integer.parseInt(s);
                sum += n;
            }
        }
        System.out.println("The sum is: "+sum);
    }
}