Refactoring a speeding ticket

In this article we go through some more refactoring techniques to write cleaner code with this homework submissions.

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The Original Submission

public static void main(String[] args) {
   caughtSpeeding (60,false);
   caughtSpeeding (65,false);
   caughtSpeeding (65,true);
 }
 public static void caughtSpeeding (int speed, boolean isBirthday) {
 if (isBirthday) {
     if(speed<=65) {       
      System.out.println(0);     
     }else if (speed>=66 && speed<=85) {       
      System.out.println(1);     
     }else if (speed>=86) {
       System.out.println(2);
     }
   }else {
     if(speed<=60) {       
       System.out.println(0);     
    }else if (speed>=61 && speed <=88) {       
      System.out.println(1);     
    }else if(speed>=81) {
       System.out.println(2);
     }
   }
 }
Code language: JavaScript (javascript)

The Refactored Code

public static void main(String[] args) {
  int useCase1 = caughtSpeeding(60, false);
  int useCase2 = caughtSpeeding(65, false);
  int useCase3 = caughtSpeeding(65, true);

  System.out.println(useCase1);
  System.out.println(useCase2);
  System.out.println(useCase3);
}

private static int caughtSpeeding(int speed, boolean isBirthday) {
  TicketCalculator ticket;
  if (isBirthday) {
    ticket = new TicketCalculatorOnBirthday();
  } else {
    ticket = new TicketCalculator();
  }
  return ticket.getTicket(speed);
}
 
public static class TicketCalculator {
  protected int NO_TICKET_MAX_SPEED = 60;
  protected int SMALL_TICKET_MIN_SPEED = 61;
  protected int SMALL_TICKET_MAX_SPEED = 80;
  protected int BIG_TICKET_MIN_SPEED = 81;

  public int getTicket(int speed) {
    if (isNoTicket(speed)) {
      return Ticket.NO_TICKET;
    } else if (isSmallTicket(speed)) {
      return Ticket.SMALL_TICKET;
    } else if (isBigTicket(speed)) {
      return Ticket.BIG_TICKET;
    } else {
      return Ticket.ERROR_CODE;
    }
  }

  private boolean isNoTicket(int speed) {
    return speed <= NO_TICKET_MAX_SPEED; 
  }

  private boolean isSmallTicket(int speed) {
    return speed >= SMALL_TICKET_MIN_SPEED && speed <= SMALL_TICKET_MAX_SPEED;
  }

  private boolean isBigTicket(int speed) {
    return speed >= BIG_TICKET_MIN_SPEED;
  }
} 

public static class TicketCalculatorOnBirthday extends TicketCalculator {
  public TicketCalculatorOnBirthday() {
    super();
    adjustSpeedLimitsForBirthday();
  }

  private void adjustSpeedLimitsForBirthday() {
    int adjustSpeedBy = 5;

    NO_TICKET_MAX_SPEED += adjustSpeedBy;
    SMALL_TICKET_MIN_SPEED += adjustSpeedBy;
    SMALL_TICKET_MAX_SPEED += adjustSpeedBy;
    BIG_TICKET_MIN_SPEED += adjustSpeedBy;
   }
}

public class Ticket {
  public final static int NO_TICKET = 0;
  public final static int SMALL_TICKET = 1;
  public final static int BIG_TICKET = 2;
  public final static int ERROR_CODE = -1;
}
Code language: PHP (php)