Question

How would I use switch statements to write a program that will take an input of length (such as 23.4) and its unit by choosing from a menu. The menu should users which unit they want to convert by choosing off of a menu. The program then should output the converted length. The units the program supports are in, ft, yd, mi, m, km. Also have the program print out an error if either the input units or the conversion units are invalid. It should also repeat this process until a 0 is entered for length.

Hint: it may be easier if you take the input length and convert it to one unit (inches for example) and then convert that to the desired unit.

Answer 1

This program will provide you an idea of how you can achieve the said task.

I have not included the calculation part to convert from one unit to other.

public class UnitCon {
   public static void main(String[] args) {
       // TODO Auto-generated method stub
       Scanner sc=new Scanner(System.in);
       String units[]= {"in", "ft", "yd", "mi", "m", "km"};
       System.out.println("Units provided are : in, ft, yd, mi, m, km \nProcess repeats till you enter a zero in length");
do {

System.out.println("Enter Length or size");
double length = sc.nextDouble();
           System.out.println("Enter units from which you will convert");
           String from=sc.nextLine();
           System.out.println("Enter units to which you want to convert");
           String to=sc.nextLine();
           double output_length=0;
           switch(from) {
           case "in":
               output_length=convert_in(length,to);
               break;
           case "ft":
               output_length=convert_ft(length,to);
               break;
           case "yd":
               output_length=convert_yd(length,to);
               break;
           case "mi":
               output_length=convert_mi(length,to);
               break;
           case "m":
               output_length=convert_m(length,to);
               break;
           case "km":
               output_length=convert_km(length,to);
               break;
           default: System.out.println("Wrong choice");
           }
           //Print output_length
       }while(length!=0);
   }
  
   public static double convert_in(double length, String to) {
       switch(to) {
       case "ft":           //Your code to convert
           break;
       case "yd":           //Your code to convert
           break;
       case "mi":           //Your code to convert
           break;
       case "m":           //Your code to convert
           break;
       case "km":           //Your code to convert
           break;
       default: System.out.println("Wrong choice");
       }
      
   }
   public static double convert_ft(double length, String to) {
       switch(to) {
       case "in":           //Your code to convert
           break;
       case "yd":           //Your code to convert
           break;
       case "mi":           //Your code to convert
           break;
       case "m":           //Your code to convert
           break;
       case "km":           //Your code to convert
           break;
       default: System.out.println("Wrong choice");
       }
   }
   public static double convert_yd(...)
   public static double convert_mi(...)
   public static double convert_m(...)
   public static double convert_km(...)

}