Question

This is my first program in java and I haven’t found any good websites like this one for C++ and it’s confusing for me because I just started writing java and I just came from C++. Anyways, concerning this code, could someone explain how to fix this code because of the line containing Scanner and/or how to simply receive inputs, because I haven’t found any simple way to translate cin >> from C++

public class input {
    public static void main(String[] args) {
        double total = 0;          
        Scanner in = new Scanner(System.in);
        System.out.println("As you enter numbers, they will be added.");
        System.out.println("Entering a non-number will stop the program.");

        while (in.hasNextDouble()) {
            double n = in.nextDouble();
            total = total + n;
            System.out.println("The total is " + total);
        }
    }
}

Answer 1

Your code works. Just make sure you have import java.util.Scanner. On a related note, use Eclipse or Netbeans as they would have told you this. Also, you should capitalize class names and put your class in a package instead of in the “default package”. I recommend “Head First Java“.

package sand1;

import java.util.Scanner;

public class Input {
    public static void main(String[] args) {
        double total = 0;
        Scanner in = new Scanner(System.in);
        System.out.println("As you enter numbers, they will be added.");
        System.out.println("Entering a non-number will stop the program.");

        while (in.hasNextDouble()) {
            double n = in.nextDouble();
            total = total + n;
            System.out.println("The total is " + total);
        }
    }
}

Here is output when I ran it. I think I might consider it a bug that I was able to hit enter with a blank line without it ending.

run:
As you enter numbers, they will be added.
Entering a non-number will stop the program.
12.2
The total is 12.2
43
The total is 55.2

a
BUILD SUCCESSFUL (total time: 11 seconds)