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-06.p
{ Advanced Pascal Programming Language Exercises
Dr. Thomas W. MacFarland
advanced_pencil-06.p
}
{ The purpose of this program is to:
1. Demonstrate the four types of variables: integer, real,
character, and Boolean.
2. Demonstrate how integer and real variables are used in
some mathematical operations.
3. Demonstrate simple functions used in Standard Pascal.
}
program Demonstrate_Multiple_Types_of_Variable_Types;
var A,B: integer;
C,D: real;
E: char;
F: boolean;
begin
A := 99;
B := 84;
C := B;
D := 456.789;
E := chr(A);
F := true;
writeln('**********************************');
writeln('A = ',A:12, ' B = ',B:12);
writeln('C = ',C:12:2,' D = ',D:12:2);
writeln('E = ',E:12, ' F = ',F:12);
writeln('**********************************');
A := round(C);
B := trunc(D);
C := sqrt(D);
D := sqr(A);
E := chr(B);
F := false;
writeln('**********************************');
writeln('A = ',A:12, ' B = ',B:12);
writeln('C = ',C:12:2,' D = ',D:12:2);
writeln('E = ',E:12, ' F = ',F:12);
writeln('**********************************');
A := ord(E);
B := succ(A);
C := sqr(D);
D := sqrt(A);
E := chr(A);
F := true;
writeln('**********************************');
writeln('A = ',A:12, ' B = ',B:12);
writeln('C = ',C:12:2,' D = ',D:12:2);
writeln('E = ',E:12, ' F = ',F:12);
writeln('**********************************');
end. {advanced_pencil-06.p}
% pc PASCAL/advanced_pencil-06.p
% a.out
**********************************
A = 99 B = 84
C = 84.00 D = 456.79
E = c F = true
**********************************
**********************************
A = 84 B = 456
C = 21.37 D = 7056.00
E = H F = false
**********************************
**********************************
A = 200 B = 201
C = 49787136.00 D = 14.14
E = H F = true
**********************************