pre ⇒ select pivot and split the array
rec ⇒ apply quicksort to the partitions
post ⇒ not much
designeds when sorting inplace was important
works best of primitive types as they can be stored in the fastest memory location
- memory access can be localised and the comparisions are direct
- those advantages are limited when sorting objects of reference type
- i that case each element of the array is just a reference to where the object really is
- so there are no local access advantages