Question

I am beginning Java programming, and I have written a program which tests how many moons each planet has. Here is a shortened version with only four of the planets.

import java.util.Scanner;
import java.util.Random;

public class one {
    public static void main(String args[]){
        //SET VARIABLES
        String zero="Mercury", one="Venus", two="Earth", three="Mars";
        //SET VARIABLES
        for (int x=1; x<=1000; x++){
            System.out.println("Moons");
            Random r = new Random();
            for (int y=1; y<=1; y++){
                int rI = r.nextInt(4);
                if (rI == 0){
                question(zero,0);
                }
                else if (rI == 1){
                question(one, 0);
                }
                else if (rI == 2){
                question(two, 1);
                }
                else if (rI == 3){
                question(three, 2);
                }
            }
        }
    }

    public static void question(String n, int num){
    Scanner input = new Scanner(System.in);
    System.out.print("How many moons does " + n + " have? ");
    int ans = input.nextInt();
    if (ans == num){
        System.out.println("Correct!");
    }
    else if (ans != num){
        System.out.println("Incorrect!");
        question(n, num);
    }
    }
}

How would I go about not having to write “else if” so many times? This becomes very tedious with more statements. Keep in mind I am a beginner, and this code is about the limit of my current abilities.

Answer 1

You could use arrays like so:

String[] planets = { "Mercury", "Venus", "Earth", "Mars" };
int moons[] = { 0, 0, 1, 2 };

and call:

if (rI >= 0 && rI < planets.length) {
    question(planets[rI], moons[rI]);
}