Question

Write a complete Java method that returns an integer. The method declares a Scanner object, then prompts the user for a series of integers in a while loop. If the user enters an integer (not a string, double, etc) then read each value entered and keep a running total (a sum). Make sure to validate that the user enters only integers. Include a sentinel value (-1) to allow the user to indicate when they are done. The method returns the total.

Answer 1

Answer:

Here is code in java.

import java.util.*;

class Main

{

 // main method of the class

public static void main (String[] args) throws java.lang.Exception

{

   try{

        // print the running total of all inputs

       System.out.println("total of all the inputs is: "+fun());

       

   }catch(Exception ex){

       return;}

}

/* function to take input from user until input is -1

 and keep a running total */

public static int fun()

{

    int in;

     //scanner class object to read the input

    Scanner scr=new Scanner(System.in);

     // variable to keep running total

    int total=0;

    System.out.println("please enter an Integer:(-1 to stop)");

     // read the input first time

    in=scr.nextInt();

    while(in!=-1)

    {

     // this loop keep taking input until input is -1.

     // calculate running total of all inputs

        total=total+in;

        System.out.println("please enter an number:(-1 to stop)::");

        in=scr.nextInt();

       

    }

     // return total of all inputs

    return total;

   

}

}

Explanation:

Create an object of scanner class in the method fun_tot(),it will take input from user.In while loop it will ask user to give input and calculate the sum of all inputs.when user enter -1 then while loop breaks and the method will return the total of all inputs given by the user.

Output:

please enter an number:(-1 to stop)::23

please enter an number:(-1 to stop)::3

please enter an number:(-1 to stop)::5

please enter an number:(-1 to stop)::76

please enter an number:(-1 to stop)::12

please enter an number:(-1 to stop)::-1

total of all the inputs is: 119