Why is list.size()>0 slower than list.isEmpty() in Java?

Question

Why is list.size()>0 slower than list.isEmpty() in Java? On other words why isEmpty() is preferable over size()>0?<

Answer 1

Your testing code is flawed.

Just reverse the order, i.e call isEmpty first and size > 0 second and you'll get the opposite result. This is due to class loading, caching, etc.