Functions, loops, if statements

Question

what situations are functions, loops, if statements used? are there situations where they could be used interchangeably?

Answer 1

Functions serve to reuse the code. You can just copy and paste contents of a function where it is called and you will be fine.
If statemens are used in control flow of a program, use them if you need one block of code executed but not the other.
Loops are there to reapeat a certain action till a given codition is false.
Generally you want to combine them, depending on a task that you have to write more efficent code.