Question

What are actual and formal parameters?

Answer 1

Actual Parameters: Actual parameters are the variables or expressions referenced in the parameter list of a subprogram.

Let's see a procedure call which lists two actual parameters named empno and amt:

1. raise_sal(empno, amt);  

Formal Parameters: Formal parameters are variables declared in a subprogram specification and referenced in the subprogram body.

Following procedure declares two formal parameters named empid and amt:

1. PROCEDURE raise_sal(empid INTEGER, amt REAL) IS current_salary REAL;