Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

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

Throw exception laps

If wants me to check if laps is less than zero and I think I'm doing that but I keep getting an error

GoKart.java
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() {
    drive(0);
  }

  public void drive(int laps) {
    // Other driving code omitted for clarity purposes
    if (laps < 0){
      throw new IllegalArgumentException("Not enough battery remains");
    }
    mBarsCount -= laps;
  }

  public void charge() {
    while (!isFullyCharged()) {
      mBarsCount++;
    }
  }

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

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

}

2 Answers

Shaun, your condition is not quite right. Try this instead:

  public void drive(int laps) {
    // Other driving code omitted for clarity purposes
    if (mBarsCount - laps < 0) {
      throw new IllegalArgumentException();
    } else {
      mBarsCount -= laps;
    }
  }

Instead of asking if laps is less than 0 you want to ask if mBarsCount minus laps is less than zero.

Thank you