ArrayList Question

[Richard Wilson]

import java.util.*;

class test {
public static void main(String args[]) {
List list=new ArrayList(5);
list.add(1,new Integer(1));
list.add(2,new Integer(2));
list.add(3,new Integer(3));
Object o=(Integer)list.get(0);
System.out.println(o);
}
}
Why it compiles error saying java.lang.IndexOutOfBoundsException?
I know List are something like array but
when array are initialized,it will be automatically given a default value.
Then,what about the subclasses of List Interface.

[Valentin Crettaz]

IndexOutOfBoundException is thrown when you give an insert index that is bigger than the current size of the list.
You insert the first element at index 1 when the list is empty (size=0), hence the exception...
If you insert at index 0, then 1, then 2 it is ok... Try it...
HIH

[Zheng Xu]

First of all, the compile for this code is OK. IndexOutOfBoundsException is a RuntimeException. Only when you run that code, it will generate this exception. You cannot add(1, new Integer(1)); when the size of that array is 0. Method public void add(int index, Object element) in ArrayList checks it.
Zheng Xu
[ February 05, 2002: Message edited by: Zheng Xu ]
[ February 05, 2002: Message edited by: Zheng Xu ]