# exercise 1.1 by erikt(at)science.uva.nl

The task was to run an age calculator program and to check if its output 
is correct.

First I stored the program in a file:

erikt@stuwww:~$ cat > 11.pl
# age calculator
print "Please enter your birth year ";
$yearOfBirth = <STDIN>;
chomp($yearOfBirth);
print "Your age is ",2007-$yearOfBirth,".\n";
^D

Then I tested the program with three birth years

erikt@stuwww:~$ perl -w 11.pl
Please enter your birth year 1943
Your age is 64.
erikt@stuwww:~$ perl -w 11.pl
Please enter your birth year 0
Your age is 2007.
erikt@stuwww:~$ perl -w 11.pl
Please enter your birth year 2008
Your age is -1.

The program does not always get it right as the first test shows.
The year entered was the birth year of John Denver (b. 31-12-1943).

* The answer 64 is wrong because John Denver died at the age of 53
* Even if Denver was alive, he would be only 63 today (Autumn of 2007) 
  and not yet 64