recursion - Base case in a recursive method

Question

A theoretical question here about the base or halting case in a recursive method, what's its standards?

I mean, is it normal not to have body in it, just a return statement?

Is it always like the following:

if (input operation value)
    return sth;

Do you have different thoughts about it?

Answer 1

The pattern for recursive functions is that they look something like this:

f( value ) 
   if ( test value )
      return value
   else
      return f( simplify value )

I don't think you can say much more than that about general cases.