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

Posted by Roshan Kashif
Roshan Kashif
2,976 Points

i'm stuck................

This is giving me an error saying "Are you sure you threw an illegal exception if the battery is less than zero

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(1);
  }

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

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

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

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

}

3 Answers

James Simshaw
James Simshaw
28,738 Points
James Simshaw
James Simshaw
28,738 Points

Hello,

Right now you're checking if the battery level equals zero when I think the challenge is wanting you to check if it is less than zero.

MUZ140265 Blessing Kabasa
MUZ140265 Blessing Kabasa
4,996 Points
MUZ140265 Blessing Kabasa
MUZ140265 Blessing Kabasa
4,996 Points

In the drive() method you have to try to call the drive(int laps) method and catch any error when it occurs. In the drive(int laps) method you can add a check to see if the remaining battery power (mBarsCount) is enough to drive the laps. When it runs out of battery you have to throw an exception with a message. This exception and message are then watched in the drive() method where you can print the message out to the console. Try this...if it helps click best answer and if it doesnt...give me a shout.

public void drive() {
    try {
      drive(1);
    } catch(IllegalArgumentException iae) {
      System.out.println(iae);
    }
  }

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

    mBarsCount -= laps;
  }
ISAIAH S
ISAIAH S
1,409 Points
ISAIAH S
ISAIAH S
1,409 Points

Try:

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(1);
  }

  public void drive(int laps) {
    // Other driving code omitted for clarity purposes
    if (laps > mBarsCount) {
      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;
  }

}