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Java Java Objects Harnessing the Power of Objects Throwing Exceptions

Jaden Kuhn
Jaden Kuhn
928 Points

throw new illegalArg problem

I have no idea what I need to add and no idea how.. Help please

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();
  }

  public void drive(int laps) {
    lapsDriven += laps;
    barCount -= laps;
    if(laps > MAX_BARS) {
     throw new IllegalArgumentException("if the requested amount of laps would make the battery less than zero.");
    }
  }
}

3 Answers

Andrew Elliott
Andrew Elliott
3,306 Points

All you gotta do is add throws IllegalArgumentException. Whenever a method intentionally throws an exception, you have to add throws ExceptionNameHere. So do this:

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();
  }

  public void drive(int laps) throws IllegalArgumentException { //I added to this line
    lapsDriven += laps;
    barCount -= laps;
    if(laps > MAX_BARS) {
     throw new IllegalArgumentException("if the requested amount of laps would make the battery less than zero.");
    }
  }
}
Jaden Kuhn
Jaden Kuhn
928 Points

Make sure you throw a new IllegalArgumentException if the requested amount of laps would make the battery less than zero. That is the error i get.. Still cant seem to work it out

i am having the same problem :/

Craig Dennis
STAFF
Craig Dennis
Treehouse Teacher

Remember you only want to change the actual bars count if the exception isn't thrown...otherwise you will change the state of the battery...and then throw an exception.

Hope that helps!