Advanced Pascal Programming Language Problems

© 1998 by Dr. Thomas W. MacFarland -- All Rights Reserved

     Instructions:   Review the following program and see if you can 
                     predict the outcome by completing a "pencil 
                     trace" of the code.  

                     Program output is provided at the end of this 
                     page.

     Compiler:       The program was prepared using Standard Pascal 
                     on a UNIX-based host computer.

% cat PASCAL/advanced_pencil-07.p
{ Advanced Pascal Programming Language Exercises
  Dr. Thomas W. MacFarland
  advanced_pencil-07.p
}

{ The purpose of this program is to:

  1.  Demonstrate the use of a user-created function.

  2.  Demonstrate simple math operations within a function.   
}

program Demonstrate_a_User_Created_Function;

var A, B, C, Sum : integer;

function Total(X, Y, Z : integer) : integer;
begin
   Total := 3 * (X - Y + (2*Z));
end; {end function Total}

begin  (* main program *)
   A   := 8;
   B   := 6;
   C   := 2;
   Sum := Total(A,B,C);
   writeln('A              = ', A:8);
   writeln('B              = ', B:8);
   writeln('C              = ', C:8);
   writeln('Computed value = ',Sum:8);
end.  {advanced_pencil-07.p}
%  pc PASCAL/advanced_pencil-07.p
%  a.out
A              =        8
B              =        6
C              =        2
Computed value =       18

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