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Java Java Objects Harnessing the Power of Objects Throwing Exceptions

Robert Zaharia
Robert Zaharia
Courses Plus Student 579 Points

Hi ! I have to throw an IllegalArgumentException if there aren't enough bars to support the laps request. 1 bar=1 lap


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) {
   int totalLaps=lapsDriven+laps;

      throw new IllegalArgumentException("You can't drive more than 12 laps");


1 Answer

your if statement is on the right track, but what you want to do is

if (barCount - laps < 1) {
  throw new IllegalArgumentException("Not enough bars");

first check if barCount will go to zero or below since it is 1 bar per lap. If it is 0 or below throw the error.