Count Compares

Question

I am new to Java, and not entirely familiar with the built-in functions. I am hoping someone can help with a simple question:
My objective is to create an array of objects, sort them using Arrays.sort(), and search them with BinarySearch(), then analyze the efficiency. I need to count the number of compares and the number of objects in the array to do this.
I have created a class which implements Comparable, but I am not sure how to get the count of compareTo() calls back to the driver program, since it is called from within the sort and search methods.
Cheers!

Answer 1

That's what I was thinking of, except that if I were you, I wouldnt' put that static stuff in a Comparator.
The Comparator can be completely standalone, and keep its own counter variable. And everything could be instance-level (i.e., non-static) in a Comparator. Also also I'd advise not creating a setCounter method -- just set the value in the constructor and increment it in compare(). No need to let some other class mess potentially with the counter.
You only need the static counter and static methods if you want to implement this functionality in the Comparable class, because in that case you have multiple separate objects working on shared state.
The cleaner solution is just to do it all in a Comparator, I think. That keeps everything pretty well-modularized.
For a really clean design, create a wrapper Comparator:
public class CountingComparator implements Comparator {
    private final Comparator wrapped;
    private int count = 0;
    public CountingComparator(Comparator wrapped) {
        this.wrapped = wrapped;
    public int compare(Object o1, Object o2) {
        count++;
        return wrapped.compare(o1, o2);
    public int getCount() {
        return count;
}Then none of your other code, including the wrapped Comparator, needs to know that any counting is going on.