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Java Java Objects Harnessing the Power of Objects Throwing Exceptions

how to solve this

stuck here

class GoKart {
  public static final int MAX_BARS = 8;
  private String color;
  private int barCount;
  private int lapsDriven;

  public GoKart(String color) {
    this.color = color;

  public String getColor() {
    return color;
  public void charge() {
    barCount = MAX_BARS;

  public boolean isBatteryEmpty() {
    return barCount == 0;

  public boolean isFullyCharged() {
    return MAX_BARS == barCount;

  public void drive() {

  public void drive(int laps) {
    if(isBatteryEmpty == true) {
    throw new IllegalArgumentException("Illegal Acess");
      lapsDriven += laps;
    barCount -= laps;


3 Answers

Jennifer Nordell
Jennifer Nordell
Treehouse Teacher

Hi there! Maybe another clarification will do the trick. You're right now checking if the battery is empty and if it is, throw an exception. But that's not really what we want. Take this scenario for example: the GoKart has 2 energy bars left, but we call the drive function and request it run 5 laps. Each lap takes up an energy bar. Your code only throws an exception if the battery is empty, but at this point, it still has 2 energy bars so no exception will be thrown. Instead, lapsDriven will be incremented by 5 and energy bars will be decremented by 5. This means that the energy bars will now be at negative 3 (-3) which shouldn't be possible.

What we're wanting here is a check to make sure that the number of laps requested does not exceed the number of energy bars we currently have.

I think you can get it with this hint, but let me know if you're still stuck! :sparkles:

means I need to compare barCount with the laps.

Okay, thanks a lot, Jennifer can I get your mail address