This is my simple ~~stupid~~ Java tip for the day: to nondestructively calculate the intersection of two Set’s (ie, retain both object), do the following:

```
```Set intersection = new HashSet(s1);
intersection.retainAll(s2);

Taken from Java Tutorials. Lessons learned: before implementing code which even vaguely seems that it should already exists, check with your favorite search engine. Also, who comes up with these function names? 🙂

## 3 responses to “Calculating the intersection of two Java sets”

" …before implementing code which even vaguely seems that it should already exists, check with your favorite search engine." Exactly what I did. Thanks, dude!

Yes! Thanks!

The name is weird, but assuming that there should be some tool for intersection and given that all other methods are NOT this tool, retailAll should be it =)

saved me the complex logic of loop within a loop 🙂 Thanks