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Java Java Objects Harnessing the Power of Objects Handling Exceptions

Help with GoKart

Question: Protect the call to kart.drive by handling the IllegalArgumentException that is thrown when not enough battery remains. Print out the message from the exception to the screen as you catch the exception

Example.java
class Example {

  public static void main(String[] args) {
    GoKart kart = new GoKart("purple");
       if (kart.isBatteryEmpty()) {
           System.out.println("The battery is empty");
    }
    try {
         kart.drive(42);
    } catch (IllegalArgumentException iae) {
      System.out.println("ALERT");
      System.out.printf("There was an error: %s\n", iae.getMessage());

    }

  }
}
GoKart.java
class GoKart {
  public static final int MAX_BARS = 8;
  private int barCount;
  private String color;
  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) {
    if (laps > barCount) {
      throw new IllegalArgumentException("Not enough batteries remain");
    }
    lapsDriven += laps;
    barCount -= laps;
  }

}
Presley Cobb
Presley Cobb
971 Points

Are you getting an error message of some sort?

Presley Cobb
Presley Cobb
971 Points

You need to add the try catch to the first drive method. You want to test the drive(1) then if it fails display the message you threw. All you did was create the error message you didnt actually throw the message. Which is admittedly confusing. You'd think the keyword throw means to actually output something to the screen but it doesn't.

I thought I had added try catch to the drive method ? I can't seem to make sense of it haha. It works on the PezDispenser. There is no errors. Maybe i'm not understanding the question properly.

2 Answers

Presley Cobb
Presley Cobb
971 Points

Sorry I actually tried the code and they want you to put the try catch block in GoKart.java. You wanna surround the drive.kart(42) with a try catch block.

Thanks for the help :)

i didn't understant what kart.drive(42); means