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

San Francisco
San Francisco
28,373 Points
Posted by San Francisco
San Francisco
28,373 Points

Part 2 of code challenge: The code in Main.java is going to throw an IllegalArgumentException when the drive method is c

Part 2 of the handling exceptions code challenge: The code in Main.java is going to throw an IllegalArgumentException when the drive method is called. Catch it and warn the user.

Here is my code, can someone please give an actual working code example (no hints or fake help please)

Main.java 
public class Main 
{
    public static void main(String[] args) 
    {
        GoKart kart = new GoKart("yellow");
        if (kart.isBatteryEmpty()) 
        {
          System.out.println("The battery is empty");
        }
        kart.drive(2);
        while (kart.isBatteryEmpty())
        catch (IllegalArgumentException)
             {
               System.out.println("Warning Brah");
             }
    }
}

4 Answers

Stone Preston
Stone Preston
42,016 Points
Stone Preston
Stone Preston
42,016 Points

Craig covers using try/catch at 3:37 of this video

you need to wrap the call to the drive method in a try/catch block (you are missing the try, you just have catch)

also remember that you must create a parameter in the catch, most of the time this is just called e for exception.

you then need to use the exception parameter e to get the message

public class Main {
    public static void main(String[] args) {
        GoKart kart = new GoKart("yellow");
        if (kart.isBatteryEmpty()) {
          System.out.println("The battery is empty");
        }
      // wrap potentially dangerous code in the try block
      try {
        kart.drive(2);
      } 
      // catch an illegal argument exception e and use e to get the message
      catch (IllegalArgumentException e) {
        System.out.println(e.getMessage());
      }
    }
}

you can read more about try/catch blocks in the documentation

Rahmat Abdhir
Rahmat Abdhir
15,198 Points
Rahmat Abdhir
Rahmat Abdhir
15,198 Points

e is the new object you created from IllegalArgumentException class, and you invoke getMessage method on this new object

San Francisco
San Francisco
28,373 Points
San Francisco
San Francisco
28,373 Points

Thank you very much Stone!

Andy Hammond
Andy Hammond
5,415 Points
Andy Hammond
Andy Hammond
5,415 Points

Where is "e.getMessage()" ?? and what are you referring to when you put the e after IllegalArgumentException?