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Java Java Objects (Retired) Harnessing the Power of Objects Throwing Exceptions

Jeremy Nash
PLUS
Jeremy Nash
Courses Plus Student 2,250 Points

illegal argument exceptions

Okay, so let's throw an IllegalArgumentException from the drive method if the requested number of laps cannot be completed on the current battery level. Make the exception message "Not enough battery remains".

Bummer! Are you sure you threw the IllegalArgumentException if the requested amount of laps would make the battery less than zero?

I've also added the drive(10); to my iae sting and gotten a bummer try again im not quite sure where i've gone wrong

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(10);
  }

  public void drive(int laps) {
    // Other driving code omitted for clarity purposes
    int numberOfLaps = mBarsCount + laps;
    if (numberOfLaps > MAX_BARS) {
   throw new IllegalArgumentException("Not enough battery remain.");
    }
     mBarsCount = numberOfLaps;
  }

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

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

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

}

1 Answer

cm21
cm21
150,854 Points

Hi Jeremy,

Currently, you're checking if the number of laps is greater than the number of bars if the battery is fully charged. What you'll want to do is rewrite that if statement so that what's actually being checked is the amount of bars remaining.

Thus,

    if (numberOfLaps > MAX_BARS) {

should be rewritten as:

    if (numberOfLaps > mBarsCount) {

Hope this helps!

Jeremy Nash
Jeremy Nash
Courses Plus Student 2,250 Points

thanks for the help i ended up figuring it out yesterday