Program to read ages into array as long as values are greater
than sentinal value.  (note that in contrast to class, reals
rather than integers are used for the data.  Also the array can
hold up to 500 values, not just 20.  This program is probably
slightly more elegant than the one written on the fly in class,
but that's a matter of taste.


	program inout;
	type
		ara500 = array[1..500] of real;
	var
		ages: ara500;
		sentinel, age: real;
		i, n: integer;
	begin
	sentinel := 0.0;
	n := 0;
	writeln('Enter age or 0.0 to quit.');
	readln(age);
	while  age > sentinel do
		begin
		n := n + 1;
		ages[n] := age;
		writeln('Enter age or 0.0 to quit.');
		readln(age);
		end;
	writeln(n, ' ages entered.');
	i := 0;
	while i > n do
		begin					{alternate code}
		i := i + 1;
		age := ages[i];				{ <- omit }
		writeln(age:5:1);			writeln(ages[i]:5:1);
		end;
	readln;
	end.

Sample output:

>Enter age or 0.0 to quit.
<2.0
>Enter age or 0.0 to quit.
<28.0
>Enter age or 0.0 to quit.
<11.5
>Enter age or 0.0 to quit.
<17.0
>Enter age or 0.0 to quit.
<0.0
>4 ages entered.
>  2.0
> 28.0
> 11.5
> 17.0