What is the difference between a "function" and a "procedure"?
Generally speaking, we all hear about the functions or procedures in programming languages. However, I just found out that I use these terms almost interchangeably (which is probably very wrong).
So, my question is:
What is the difference in terms of their functionality, their purpose and use?
An example would be appreciated.
Answer
A function returns a value and a procedure just executes commands.
The name function comes from math. It is used to calculate a value based on input.
A procedure is a set of command which can be executed in order.
In most programming languages, even functions can have a set of commands. Hence the difference is only in the returning a value part.
But if you like to keep a function clean, (just look at functional languages), you need to make sure a function does not have a side effect.