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

Tara Edwards
Tara Edwards
6,521 Points

Am I writing the throw command wrong?

I get 'symbol missing' errors. Which symbol am I missing?

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
   int mBarsCount = mBarsCount - laps;
    if(mBarsCount < 0){
      throw IllegalArgumentException("Not enough battery remains");
    }
  }

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

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

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

}

2 Answers

Hi Tara,

That's a good attempt! There are a few things that need to be fixed.

// mBarsCount is already defined. remove the int type here
int mBarsCount = mBarsCount - laps;

// this is close, but we need to throw a 'new' error
throw IllegalArgumentException("Not enough battery remains");

// check if mBarsCount is already at zero before attempting to subtract from it
// if mBarsCount <= 0, throw error, else decrement mBarsCount

Cheers

Seth Kroger
Seth Kroger
56,413 Points

throw needs an Exception object (actually a Throwable object, which Exception is a subclass of) to throw. You need to use the new keyword to create the exception you want to throw.

throw new IllegalArguemntException("message");