Is there a better way to combine two string sets in java?

Question

I need to combine two string sets while filtering out redundant information, this is the solution I came up with, is there a better way that anyone can suggest? Perhaps som

Answer 1

If you care about performance, and if you don't need to keep your two sets and one of them can be huge, I would suggest to check which set is the largest and add the elements from the smallest.

Set newStringSet = getNewStringSet();
Set oldStringSet = getOldStringSet();

Set myResult;
if(oldStringSet.size() > newStringSet.size()){
    oldStringSet.addAll(newStringSet);
    myResult = oldStringSet;
} else{
    newStringSet.addAll(oldStringSet);
    myResult = newStringSet;
}

In this way, if your new set has 10 elements and your old set has 100 000, you only do 10 operations instead of 100 000.