list.removeAll(otherList) - wrong result

Hi guys,

I have 2 Lists:

1.carList

2.documentList

*both contain the same type: car PLUS I have overloaded the hashCode and equals of car

carList has 1106 items

documentList has 88 items

I would like to remove the 88 items of documentList from the carList.

(simple math: 1106-88=1018)

By doing this:

(1)

this.carList.removeAll(documentList);

the carList.size() = 1013 (?!?!)

by doing this:

(2)

for (int x=carList.size()-1; x>=0; x--)

{

Car cx = (Car) carList.get(x);

for (int i=documentList.size()-1; i>=0; i--)

{

Car ci = (Car) documentList.get(i);

if (cx.equals(ci))

{

carList.remove(x);

documentList.remove(i);

break;

}

}

}

I get 1018 (correct)

Question: Why am I getting the wrong result in option 1? (once again, I have overloaded the hashCode and equals of car)

[1317 byte] By [xianwinwina] at [2007-11-26 16:51:35]