Need to reprompt a statement, but my code continues to the next statement,

Question

In the while statement, after you type a wrong direction i get an error but then procedes to the next question. How can i format it to reprompt for a valid direction? don't know if i should use do while or not to me this seems like the correct approach to take but it doesn't seem to work

import javax.swing.JOptionPane;
public class taxiService {

public static void main(String [] args) {

//Declare constants
double fareCharge = 5;
double totalMiles = 0;
double finalFareCharged = 0;
double finalxCoord = 0;
double finalyCoord = 0;
double numOfMiles = 0;
double finalCoord = 0;
String error = "Invalid data, please enter valid data!";

String directions = "";
boolean reprompt = true;
//Prompt for direction and miles

while (reprompt) {
   totalMiles = numOfMiles + numOfMiles;
   directions = JOptionPane.showInputDialog(null, "Please enter a direction: ");
   if (directions.equalsIgnoreCase("East")) {
      finalxCoord = finalxCoord + numOfMiles;
      reprompt = false;
      }
      else if (directions.equalsIgnoreCase("West")) {
               finalxCoord = finalxCoord - numOfMiles;
               reprompt = false;
               }
             else if (directions.equalsIgnoreCase("North")) {
                     finalyCoord = finalyCoord + numOfMiles;
                     reprompt = false;
                     }
                     else if (directions.equalsIgnoreCase("South")) {
                             finalyCoord = finalyCoord - numOfMiles;
                             reprompt = false;
                             }
             else {
                 reprompt = true;
                 JOptionPane.showMessageDialog(null, error);

        }
   numOfMiles = Double.parseDouble(JOptionPane.showInputDialog(null, "Please enter distance in miles: "));
   if (numOfMiles > 0) {
   JOptionPane.showMessageDialog(null, "miles: " + totalMiles);
   }
   else 
   JOptionPane.showMessageDialog(null, error);


   }
}
}

Answer 1

Move the second question outside the loop. I think this is what you originally had in mind but made a logic error by putting the second question in the loop.

import javax.swing.JOptionPane;
public class taxiService {

public static void main(String [] args) {

//Declare constants
double fareCharge = 5;
double totalMiles = 0;
double finalFareCharged = 0;
double finalxCoord = 0;
double finalyCoord = 0;
double numOfMiles = 0;
double finalCoord = 0;
String error = "Invalid data, please enter valid data!";

String directions = "";
boolean reprompt = true;
//Prompt for direction and miles

while (reprompt) {
   totalMiles = numOfMiles + numOfMiles;
   directions = JOptionPane.showInputDialog(null, "Please enter a direction: ");
   if (directions.equalsIgnoreCase("East")) {
      finalxCoord = finalxCoord + numOfMiles;
      reprompt = false;
      }
      else if (directions.equalsIgnoreCase("West")) {
               finalxCoord = finalxCoord - numOfMiles;
               reprompt = false;
               }
             else if (directions.equalsIgnoreCase("North")) {
                     finalyCoord = finalyCoord + numOfMiles;
                     reprompt = false;
                     }
                     else if (directions.equalsIgnoreCase("South")) {
                             finalyCoord = finalyCoord - numOfMiles;
                             reprompt = false;
                             }
             else {
                 reprompt = true;
                 JOptionPane.showMessageDialog(null, error);

        }
   }
   numOfMiles = Double.parseDouble(JOptionPane.showInputDialog(null, "Please enter distance in miles: "));
   if (numOfMiles > 0) {
   JOptionPane.showMessageDialog(null, "miles: " + totalMiles);
   }else {
   JOptionPane.showMessageDialog(null, error);


   }
}
}

OR

Add continue; after showing the error JOptionPane. This will force it to jump back to the start of the loop and prompt again.