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Java Java Objects Harnessing the Power of Objects Throwing Exceptions

David Kirk
David Kirk
5,319 Points

having issues generating the exception...

attempting to generate exception if laps exceed MAX_BARS and not getting any luck.

public void drive(int laps) { int newLap = lapsDriven += laps; barCount -= laps; if (newLap > MAX_BARS) { throw new IllegalArgumentException("Too many laps!!!"); } lapsDriven = newLap; }

GoKart.java
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() {
    drive(1);
  }

  public void drive(int laps) {
    int newLap = lapsDriven += laps;
    barCount -= laps;
    if (newLap > MAX_BARS) {
      throw new IllegalArgumentException("Too many laps!!!");
    }
    lapsDriven = newLap;
  }
}

1 Answer

Hi David,

You want to see if barCount is less than laps (or laps is greater than barCount). i.e. you don't have enough bars to complete the number of laps requested. If it is, throw the error, otherwise (else) deduct laps from barCount and add laps to lapsDriven (that's the existing lines of code).

I hope that helps,

Steve.