TOPS-20 PASCAL Language Manual - Bitsavers

PROCEDURES AND FUNCTIONS
As a result of this call, the list of integers is written in the array
ARR. The value of this array is then returned to the program unit
that called the procedure READ WRITE.
Example 2
PROCEDURE MIN_MAX_AVG (VAR Miny Max : Ran~e;
VAR Avg : REAL; A : List);
VAR Sum, NMax~ NMin~ J : INTEGER;
BEGIN
M3X := Ael); Min:= Max; Sum:= Max;
NMax := 1; NMin:= 1;
FOR J := 2 TO NUMBER DO
BEGIN
Sum := Sum + A[JJ~
IF A[J) > Max THEN
BEGIN Max := AeJJ;
NMa>: : =:: 1
END
ELSE IF A[JJ = Max THEN
NMax := NMax + 1;
IF AEJJ < Min THEN
BEGIN Min := A[J);
NMin !:=: 1
END
ELSE IF A[JJ
Min THEN
NMin : :~: NMin + 1
END;
AVG := Sum/NUMBER;
WF~ I TELN;
WRITELN('Maximum =',Max:4,', occurring',NMax:4, , times');
WFnTELN;
WRITELN('Minimuffi =', Min:4,', occurring', NMin:4,' times');
WFnTELN;
WRITELN ('Average value (truncated) =', TRUNC(Avg):10);
WRITELN ('Average value ='r Avg : 20)
END;
This procedure computes the minimum, maximum, and average values in
array A. It also counts the number of times the minimum and maximum
values occurred, and stores those numbers in NMin and NMax. The
WRITELN statements print the results of each of those computations.
Min, Max, and Avg are formal variable parameters. Their values, as
assigned in the procedure MIN_MA.X_AVG, are returned to the calling
program unit and can be used for further computations in the program.
A is specified as a value parameter because its value does not change
in the procedure.
The following is a valid procedure call to the procedure:
The values of the formal parameters Min, Max, and Avg are returned to
the actual parameters Minimum, Maximum, and Average, which were
defined in the main block of the program.
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