Quicksort superiority over Heap Sort

Question

Heap Sort has a worst case complexity of O(nlogn) while Quicksort has O(n^2). But emperical evidences say quicksort is superior. Why is that?

Answer 1

Here's a couple explanations:

http://www.cs.auckland.ac.nz/software/AlgAnim/qsort3.html

http://users.aims.ac.za/~mackay/sorting/sorting.html

Essentially, even though the worst case for quick sort is O(n^2) it on average will perform better. :-)