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

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;

}

}

Step-by-step 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