Java: Finding how many words appear in BOTH data sources?

Question

Hi!

I'm trying to figure out if there is an easy way to count the number of words that appear in small paragraph (#1) and small paragraph (#2).

Generally, Im determining how much overlap there is in these paragraphs on a word by word basis. So if (#1) contains the word "happy" and (#2) contains the word "happy" that would be like a +1 value.

I know that I could use a String.contains() for each word in (#1) applied to (#2). But I was wondering if there is something more efficient that I could use

Answer 1

You can create two sets s1 and s2, containing all words from first and second paragraph respectively, and intersect them: s1.retainAll(s2). Sounds easy enough.

update
Works for me

    Set<String> s1 = new HashSet<String>(Arrays.asList("abc xyz 123".split("\\s")));
    Set<String> s2 = new HashSet<String>(Arrays.asList("xyz 000 111".split("\\s")));
    s1.retainAll(s2);
    System.out.println(s1.size());

Don't forget to remove empty word from both sets.