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 trialMichael Dinkins
9,483 Pointsjava objects throwing exceptions
Bummer! Make sure you throw a new IllegalArgumentException if the requested amount of laps would make the battery less than zero.
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) throws IllegalArgumentException {
lapsDriven += laps;
barCount -= laps;
if (barCount > 0) {
throw new IllegalArgumentException();
}
}
}
1 Answer
Steve Hunter
57,712 PointsHi Michael,
You want to capture the error first, then do the logic part of the drive
method. What we're trying to catch is a situation where you don't have enough barCount
to drive the number of laps
requested. So, if barCount
is less than laps
, don't change any of the values because the kart won't drive anywhere, and throw the IllegalArgumentException()
.
Inside, drive(int laps)
start with an if
statement. Test if laps > barCount
, if it is, throw the exception; else do the maths piece that's already in the method.
Here's what I came up with - I hope it helps and makes sense to you.
public void drive(int laps) {
if(laps > barCount){
throw new IllegalArgumentException();
} else {
lapsDriven += laps;
barCount -= laps;
}
}
Good luck!
Steve.
Steve Hunter
57,712 PointsSteve Hunter
57,712 PointsP.S. the challenge passes with or without the
throws IllegalArgumentException
- I suspect having it in place is best practice.