Welcome to the Treehouse Community

The Treehouse Community is a meeting place for developers, designers, and programmers of all backgrounds and skill levels to get support. Collaborate here on code errors or bugs that you need feedback on, or asking for an extra set of eyes on your latest project. Join thousands of Treehouse students and alumni in the community today. (Note: Only Treehouse students can comment or ask questions, but non-students are welcome to browse our conversations.)

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and a supportive community. Start your free trial today.

Java Java Objects Harnessing the Power of Objects Throwing Exceptions

Kendhall Lebron Ruiz
PLUS
Kendhall Lebron Ruiz
Courses Plus Student 1,143 Points

I am stuck with the drive method

"Modify the drive method to define a parameter of how many laps should be driven. Update the method body to handle the new parameter." I've been stuck on this question for like 20 minutes and don't know what to do.

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) {
    lapsDriven += laps;
    barCount = laps-- ;
    if(barCount < 0){
    throw new IllegalArgumentException("Not enough batteries");
    }
  }
}

1 Answer

First off, don't you want to check and throw the exception before you change anything? Move the check to the beginning.

Also, examine how you modify barCount closely. Don't you want to subtract from barCount?