Prevent duplicate entries in arraylist
Posted
by
timyh
on Stack Overflow
See other posts from Stack Overflow
or by timyh
Published on 2012-04-01T05:16:38Z
Indexed on
2012/04/01
5:29 UTC
Read the original article
Hit count: 194
Say I create some object class like so
public class thing {
private String name;
private Integer num;
public oDetails (String a, Integer b) {
name = a;
num = b;
}
...gets/ sets/ etc
Now I want to create an arraylist to hold a number of this object class like so.
ArrayList<thing> myList = new ArrayList<thing>;
thing first = new thing("Star Wars", 3);
thing second = new thing("Star Wars", 1);
myList.add(first);
myList.add(second);
I would like to include some sort of logic so that in this case...when we try and add object "second" rather than add a new object to the arrayList, we add second.getNum() to first.getNum(). So if you were to iterate through the ArrayList it would be
"Star Wars", 4
I am having trouble coming up with an elegant way of handling this. And as the arraylist grows, searching through it to determine if there are duplicate name items becomes cumbersome. Can anyone provide some guidance on this?
© Stack Overflow or respective owner