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Java Java Objects Harnessing the Power of Objects Handling Exceptions

Karan Shah
Karan Shah
492 Points

It is showing error, please rectify the mistake

Showing error, what is the mistake?

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( iae );

}
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 battery remains");
    }
    lapsDriven += laps;
    barCount -= laps;
  }

}

1 Answer

Hi there,

You've pretty much done that right, but you need to call getMessage() on the iae instance:

    try{
      kart.drive(42);
    } catch(IllegalArgumentException iae){
      System.out.println(iae.getMessage());
    }
  }

Steve

Karan Shah
Karan Shah
492 Points

What is the reason to call getMessage()?

Hi there,

The getMessage method returns a string representing the type of exception being thrown. The iae itself is an instance of an error so can't be printed itself, the string returned from getMessage() can be printed.

Steve.