MetricConvertor

import java.util.Scanner;

public class MetricConvertor {
    private static final double mm = 1000;
    private static final double cm = 100;
    private static final double mi = 0.000621371192;
    private static final double in = 39.3700787;
    private static final double km = 0.001;
    private static final double feet = 3.2808399;
    private static final double yards = 1.0936133;
    private static final double meters = 1;

    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        double mm = 1000;
        double cm = 100;
        double mi = 0.000621371192;
        double in = 39.3700787;
        double km = 0.001;
        double feet = 3.2808399;
        double yards = 1.0936133;
        double meters = 1;
        System.out.print("Enter the value of what you want to convert: ");
        double number = Double.parseDouble(sc.nextLine());
        System.out.print("Enter the type of the unit you enter(mm,cm,mi,in,km,ft,yd):");
        String unit = sc.nextLine();
        System.out.print("Enter the type of the unit you want to convert to(mm,cm,mi,in,km,ft,yd): ");
        String convert = sc.nextLine();
        double result = number/input(unit)*output(convert);
        System.out.printf("You converted %f %s to %f %s.", number,unit,result,convert);

    }

    private static double input(String unit){
         switch (unit){
             case "mm":
                 return mm;
             case "cm":
                 return cm;

             case "mi":
                 return mi;

             case "km":
                 return km;

             case "ft":
                 return feet;

             case "yd":
                 return yards;

             default:
                 return meters;

         }
    }


    private static double output(String convert){
        switch (convert){
            case "mm":
                return mm;
            case "cm":
                return cm;

            case "mi":
                return mi;

            case "km":
                return km;

            case "ft":
                return feet;

            case "yd":
                return yards;

            default:
                return meters;

        }
    }

}