Arraylist

[adam Lui]

 import java.util.*;
public class TestBadLegacy {
public static void main (String[] args){
List<Integer> myList = new ArrayList<Integer>();
myList.add(4);
myList.add(6);
Inserter in = new Inserter();
in.insert(myList);

}
}
 
class Inserter {
void insert (List list) {

List tempList = new ArrayList();

tempList = list; //copy list's to tempList

list.add(343); //add value to list ONLY

Iterator it = list.iterator();
while (it.hasNext()){
System.out.println(it.next());
}

System.out.println("temp's time"); //display tempList's value
Iterator itTemp = tempList.iterator();
while (itTemp.hasNext()){
System.out.println("Temp " + itTemp.next());
}
}
}
 
   

ok...i add value at - list.add(343); -
and "itTemp" was added value 343 to, too, but why and how to avoid?
how i could possily prevent this from happening?

[Maneesh Godbole]

Originally posted by adam lui:
how i could possily prevent this from happening?

Try List tempList = new ArrayList(list);

[Corey McGlone]

List tempList = new ArrayList();

tempList = list; //copy list's to tempList

At this point, tempList and list both reference the exact same ArrayList object. You don't actually have two lists, but two references to one list. If you want something added to one list but not another, you first need to have two lists to work with.