On Tue, Nov 17, 2009 at 2:52 AM, Sean Luke <[log in to unmask]> wrote:

On Nov 17, 2009, at 11:21 AM, Paul Smaldino wrote:

public  Bag findNotPlayed(Bag neighbors){
for(int k = 0; k < neighbors.numObjs; k++){
 Agent a = (Agent)neighbors.get(k);
 if(a.equals(this) || a == this){
    neighbors.removeNondestructively(k);
    break;
    }
}
int num = neighbors.numObjs;
for(int i=0; i < num; i++){
 Agent a = (Agent)neighbors.get(i);
 if(a.played)
 neighbors.removeNondestructively(i);
 }
return neighbors;
}


In the second for loop, when I used i < neighbors.numObj, the method removed
only one of the two agents who had played. When I substituted the local
variable num, I got a IndexOutOfBounds exception.

Every time you remove an object from the bag, it shrinks in size (that is, neighbors.numObjs decreases by one).  You test for this in the first example; but in the second, you've already loaded the very first numObjs into num and continue using that same number.

Sean