JAVA Write a program that requests the user input positive numbers until they input -1, then prints the sum of all numbers.
Sample run:
Enter positive numbers (-1 to stop)
3
7
8
-1
Sum is 18

The program is an illustration of loops.

Loops are used to carry out repetition operations; examples are the for-loop and the while-loop.

The program in Java, where comments are used to explain each line is as follows:

import java.util.*;

public class Main

{

public static void main(String[] args) {

    //This creates a scanner object

 Scanner input = new Scanner(System.in);

 //This initializes sum to 0, and declares num

 int sum = 0; int num;

 //This gets input from the user

 num = input.nextInt();

 //The loop is repeated until the user enters -1

 while(num!=-1){

     //This if-condition ensures that, only positive numbers are added

     if(num > 0){

         sum+=num;    

     }

     //This gets another input from the user

     num = input.nextInt();

 }

 //This prints the sum of all positive numbers gotten from the user

 System.out.print(sum);

}

}

The above program is implemented using a while loop

Read more about similar programs at:

link

import java.util.Scanner;

public class JavaApplication33 {

   public static void main(String args[]) {

     Scanner scan = new Scanner(System.in);

     int total = 0;

     System.out.println("Enter positive numbers (-1 to stop)");

     while (true){

         int num = scan.nextInt();

         if (num == -1){

             break;

         }

         else{

             total += num;

         }

     }

     System.out.println("Sum is "+total);

}

}

I hope this helps!