Repeating the function invocation recursively

As a programmer, especially in object-oriented programming, we usually use the iteration technique to repeat our process. For now, we will discuss the recursion method to repeat our process and use it in the functional approach. Basically, recursion and iteration perform the same task, which is to solve a complicated task piece by piece then combine the results. However, they have a difference. The iteration process emphasizes that we should keep repeating the process until the task is done, whereas recursion emphasizes that need to break the task up into smaller pieces until we can solve the task, then combine the result. We can use the iteration process when we need to run a certain process until the limit is reached or read a stream until it reaches eof(). Also, recursion can give the best value when we use it, for instance, on the calculation of a factorial.

Performing the iteration procedure to repeat the process

We will start with the iteration...