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Java Java Objects (Retired) Harnessing the Power of Objects Throwing Exceptions

How to make the throw exception for the car drive? I try different ways, but I still get errors.

How is that going to work? should I get a new variable? or use if statement?

public class GoKart {
  public static final int MAX_BARS = 8;
  private String mColor;
  private int mBarsCount;

  public GoKart(String color) {
    mColor = color;
    mBarsCount = 0;

  public String getColor() {
    return mColor;

  public void drive() {

  public void drive(int laps) {
    // Other driving code omitted for clarity purposes
    int newLabs = mBarsCount + laps;
    throw new IllegalArgumentException ("Not enough battery remains");
    mBarsCount -= laps;


  public void charge() {
    while (!isFullyCharged()) {

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

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


1 Answer

Craig Dennis
Craig Dennis
Treehouse Teacher

I think you only want to throw the exception if the total number of bars minus the laps is less than zero.

Good job thinking to stick the results in that variable. You should set the mBarsCount to it after you test for the exception.

Thanks for you answer, Now I get the question. :)