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Java Java Objects Harnessing the Power of Objects Throwing Exceptions

Posted by Dearce Goodman
Dearce Goodman
2,331 Points

I feel close just can't figure what to do next

Im throwing the exception, am I missing something

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(9);
  }

  public void drive(int laps) {
    lapsDriven += laps;
    barCount -= laps;

    int newAmount = lapsDriven + laps;
    if(newAmount > MAX_BARS){
      throw new IllegalArgumentException("Too many laps ");
    }
      lapsDriven =newAmount;
  }
}

4 Answers

KRIS NIKOLAISEN
KRIS NIKOLAISEN
54,972 Points

The error message is: Bummer: Make sure you throw the exception before you change the barCount and lapsDriven fields. You don't want to update these values if there is an exception. So the verification should come first

  public void drive(int laps) { 
    if (laps > barCount){
      throw new IllegalArgumentException("Too Many Laps");
    }

    lapsDriven += laps;
    barCount -= laps;
  };
KRIS NIKOLAISEN
KRIS NIKOLAISEN
54,972 Points
KRIS NIKOLAISEN
KRIS NIKOLAISEN
54,972 Points

You are already incrementing lapsDriven here:

lapsDriven += laps;

So with the following you increment a second time

 int newAmount = lapsDriven + laps;

Then you check this against the maximum bar count. You should be checking if laps is greater than the current bar count. Do this verification and raise your error before you update lapsDriven and barCount.

Dearce Goodman
Dearce Goodman
2,331 Points

Thanks I finally saw my mistake, thanks for the help

Dearce Goodman
Dearce Goodman
2,331 Points
Dearce Goodman
Dearce Goodman
2,331 Points

I checked the laps against the barCount but i still getting this error. Make sure you throw the exception before you change the barCount and lapsDriven fields.

I must of missed something in the video.

Dearce Goodman
Dearce Goodman
2,331 Points
Dearce Goodman
Dearce Goodman
2,331 Points

Thanks for the help problem solved