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Java Java Objects Harnessing the Power of Objects Throwing Exceptions

IllegalArgumentException Exercise

I am trying to put an if loop into my code exercise and spit out an Illegal Argument Exception, but I cannot get it to pass. I keeps telling me to make sure that the error is thrown if the int laps is greater than the MAX_BARS. What am I doing wrong?

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 (laps > MAX_BARS) {
      throw new IllegalArgumentException("Battery is empty");
    lapsDriven += laps;
    barCount -= laps;

1 Answer

Chris Freeman
Chris Freeman
Treehouse Moderator 67,637 Points

Hey Gretchen Zinsmeister, you are very close!

The error is to be thrown if there aren't enough bars remaining to support the laps request.

So compare laps to barCount instead of MAX_BARS

Post back if you need more help. Good luck!!!

That worked. Thank you so much!