Java - Prvi zadatak

package testiranjeZira;


import java.util.*;

public class zadaciUPR {



    // Napišite program koji ispuje pređeni put u metrima, centrima, milimetrima na osnovu unesenog broja kilometara




    public static double metri(double km){

        return km*= 1000;
    }

    public static double centimetri(double km){

        return km *= 100000;

    }

    public static double milimetri(double km){
        return km *= 1000000;
    }

    public static void main(String args[]){


        Scanner input = new Scanner(System.in);


        System.out.println("Odaberite operacije 1 (km-m), 2 (km-cm), 3 (km-mm): ");

        double km = 200;

        int izbor = input.nextInt();


        switch(izbor){
            case 1:
                System.out.println("Za " + 20000 + "km" +  "pređeni put u metrima iznosi: " + metri(km));
                break;
            case 2:
                System.out.println("Za " + 20000 + "km" +  "pređeni put u centrimetrima iznosi: " + centimetri(km));
                break;
            case 3:
                System.out.println("Za " + 20000 + "km" +  "pređeni put u milimetrima iznosi: " + milimetri(km));
                break;
            default:
                break;
        }

    }
}