Question

In Java is there an object like a “Set” that can contain only unique string values, but also contain a count on the number of occurrences of the string value?

The idea is simple

With a data set ala…

A
B
B
C
C
C

I’d like to add each line of text to a Set-like object. Each time that a non-unique text is added to the set I’d like to also have a numeric value associated with the set to display how many times it was added. So if I ran it on the above data set the output would be something like:

A : 1
B : 2
C : 3

any ideas?

Answer 1

Map<String, Integer> would be the best bet, to put in words what you want to do is to Map the amount of occurrences of a string. Basically have something like this:

public void add(String s) {
    if (map.containsKey(s)) {
        map.put(s, map.get(s) + 1);
    } else {
        map.put(s, 1);
    }
}