The Fibonacci sequence is a series of numbers where each number in the sequence is
the sum of the preceding two numbers, starting with 0 and 1. It is natural to
consider a recursive function to calculate a subset of the Fibonacci sequence, but
this may not be the most efficient mechanism.
It can be very useful to check the execution time of a group of swift statements or swift
function when evaluating the most efficient way to perform a task. In this article three
different mechanisms are used to measure the execution time to sum up 1000 random numbers.