ArrayIndexOutOfBoundsException

[Natalia Sandacz]

Hi!
I wanted to compile such program:

class Rectangle{
  int length, breadth;
  void show(int x, int y){
  length = x;
  breadth = y;
  }
  int calculate(){
  return(length * breadth);
  }
}
public class EnterValuesFromKeyboard{
  public static void main(String[] args) {
  Rectangle rectangle = new Rectangle();
  int a = Integer.parseInt(args[0]);
  int b = Integer.parseInt(args[1]);
  rectangle.show(a, b);
  System.out.println(
  " you have entered these values : " +  a  + " and " +  b);
  int area = rectangle.calculate();
  System.out.println(" area of a rectange is  : " + area);
  }
}

Unfortunately it doesn't work and I get : Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 0
at EnterValuesFromKeyboard.main(Rectangle.java:14)
How can I fix it?

[Jeanne Boyarsky]

Natalia,
Welcome to CodeRanch!

As a matter of semantics, your program is giving a runtime error which means it does compile.

The error implies you are calling it as "java Rectangle" instead of "java Rectangle 1 2". If this is not the case, can you show how you are running the program?

[Natalia Sandacz]

I should name class "Rectangle 1 2" instead "Rectangle"?

[Jeanne Boyarsky]

No. The name is good. When you run the program, you can optionally supply arguments. This is where the 1 and 2 fit in.

so:
javac Rectangle.java
java Rectangle 1 2

[Natalia Sandacz]

I use JCreator. When I run the program I can't supply any arguments (or I don't know how to do it). In build output I have: Process completed. but in General output I have Exception.

[John Jai]

Hi,

I myself have not used the JCreator IDE. But can you try the steps under Setting Up Command-Line Arguments topic in a JCreator tutorial link -> a JCreator tutorial and give 1 2 as arguments for the Main method as given in the picture?

Its similar to running java Rectangle 1 2 i think.

[Wouter Oet]

I would advise you not to use an IDE for now. At this point you're not familiar with the basics and using by using just a text-editor and a compiler you'll pick those basics up much faster.

[Natalia Sandacz]

It works. Thanks a lot!