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 trialAvery Freeman-wheaton
2,273 PointsTrouble with throw new IllegalArgumentException in GoKart exercise
Hi,
I seem to be having trouble now with the
throw new IllegalArgumentException("Not enough battery remains");
Here's my codeblock I tried, but can't get to work:
public void drive(int laps) {
// Other driving code omitted for clarity purposes
mBarsCount -= laps;
int newLapsLeft = mBarsCount - laps;
if (newLapsLeft > MAX_BARS) {
throw new IllegalArgumentException("Not enough battery remains");
}
mBarsAmount = newLapsLeft;
}
Not really sure how to do this. I tried to put it in as similarly as the demonstration showed, but I just don't seem to be able to get it.
Thanks! -Avery
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(int laps) {
// Other driving code omitted for clarity purposes
mBarsCount -= laps;
int newLapsLeft = mBarsCount - laps;
if (newLapsLeft > MAX_BARS) {
throw new IllegalArgumentException("Not enough battery remains");
}
mBarsAmount = newLapsLeft;
}
public void drive() {
drive(1);
}
public void charge() {
while (!isFullyCharged()) {
mBarsCount++;
}
}
public boolean isBatteryEmpty() {
return mBarsCount == 0;
}
public boolean isFullyCharged() {
return mBarsCount == MAX_BARS;
}
}
1 Answer
Gene Osborne
8,630 PointsTake notice of these two lines of code:
mBarsCount -= laps;
int newLapsLeft = mBarsCount - laps;
You are substracting the laps twice!
That being said, you are overthinking it. All you need to do is check if it can be done:
public void drive(int laps) {
// Other driving code omitted for clarity purposes
if(mBarsCount <= laps) throw new IllegalArgumentException("Not enough battery remains");
else mBarsCount -= laps;
}
Avery Freeman-wheaton
2,273 PointsAvery Freeman-wheaton
2,273 PointsThank you! That really helped!
I really appreciate the help in these forums. Sorry it took me so long to reply. Have a nice day!