Does java have a Frequency table?

Question

Does Java have a built in Frequency Table? I remember using one in one of my classes and I know Python has one, but I do not remember if I built one on my own or if Java has one for use.

Answer 1

I assume by "frequency table" you mean a map of value-to-count.
The answer is no.

It's not much of a stretch to create a well-behaved one though:

Map<T, Integer> freq = new HashMap<T, Integer> () {
    @Override
    public Integer get(Object key) {
        return containsKey(key) ? super.get(key) : 0;
    }
}

Then when using you don't have to clutter your code with null checks when getting a frequency:

freq.get(value);  // returns zero for not found

Or when incrementing:

freq.put(value, freq.get(value) + 1); // always works, won't throw NPE etc

Answer 2

Not built-in but you can check Apache Commons Statistics. It has an easy Frequency table builder that allows to find frequency, cumulative frequency, counts, etc.