I have two arrayLists
ArrayList one = {A, B, C, D, E}
ArrayList two = {B, D, F, G}
I want to have my final ArrayList which will have All the elements of one and the elements which are only in two and not in one.
So ArrayList final = {A, B, C, D, E, F, G}.
How can I do this?
Either:
Set<Foo> fooSet = new LinkedHashSet<>(one);
fooSet.addAll(two);
List<Foo> finalFoo = new ArrayList<>(fooSet);
or
List<Foo> twoCopy = new ArrayList<>(two);
twoCopy.removeAll(one);
one.addAll(twoCopy);
two list. You can two.removeAll(one); one.addAll(two)for (Object x : two){
if (!one.contains(x))
one.add(x);
}
assuming you don't want to use the set suggested in the comment. If you are looking for something fancier than this please clarify your question.
List this is a perfectly acceptable way of doing it. Depending on the size of you data set a Set or SortedList might give you better performance even if you have to then copy back to a List
Try this kind of thing. As Set doesn't allow duplicates you can add only the changes
ArrayList<String> a=new ArrayList<>();
a.add("a");
a.add("b");
ArrayList<String> b=new ArrayList<>();
a.add("a");
a.add("c");
Set<String> s=new HashSet<String>();
s.addAll(a);
s.addAll(b);
a=new ArrayList<>(s);
for(String r:a){
System.out.println(r);
}
main and where to find normal imports. Just include the code.you can do something like this:
ArrayList<Object> result = new ArrayList<>();
result.addAll(one);
for(Object e: two){
if(!result.contains(e))
result.add(e);
}
result. You could just do ArrayList result = new ArrayList(one); instead of the first loop.
Setpossible? This requires that your items in list one are unique.Setis available in 1.2. The question you must answer is: do you want any duplicates in your final list/set?