Function procedures

So far we have encountered two possibilities to pass a result from a procedure body to its calling place: the result is either assigned to a non-local variable or to a variable parameter. There exists a third method: the function procedure. It permits the use of the computed result (as an intermediate value) in an expression. The function procedure identifier stands for a computation as well as for the computed result. The procedure declaration is characterized by the indication of the result’s type behind the parameter list. As an example, we rephrase the power computation given above.