What is the work of return function in C?

Answer 1

It returns values back to where the function was called.

Answer 2

https://www.sololearn.com/Course/CPlusPlus/
https://www.sololearn.com/Course/CSharp/

^Read through any of the available C-based languages provided here. It's something you learn in the first chapter or two. For the most part, the concept holds true between most languages.

Answer 3

It has two uses:
1. It immediately returns back control to the previous function from where it was called
2. It is used to return values from functions

eg In main() function, if you return 0, it tells the operating system that the program terminated normally.

Answer 4

Take a look at this... maybe it'll help you out:
https://msdn.microsoft.com/en-us/library/sta56yeb.aspx