Semicolon at the ends of if-statements and functions in C

Question

I just ran into some code that overuse semicolons, or use semicolon for different purposes that I am not aware of.

I found semicolons at the end of if-statements and

Answer 1

The first semicolon (after the if-statement) is just an empty expression which does nothing. I fail to see any point of having it there.

The second semicolon (after the function) is an error since it is outside of any block of code. The compiler should give a warning.