# exercise 2.1 by erikt(at)science.uva.nl

SOFTWARE

# read a number
print "Please enter a number: ";
$nbr = <STDIN>;
chomp($nbr);

# print a multiplication table with for
for ($i=1;$i<=12;$i++) {
   # print an extra space before numbers under 10 to achieve alignment
   if ($i < 10) { $s = " "; } else { $s = ""; }
   print "$nbr * $s$i = ",$nbr*$i,"\n";
}
print "\n"; # extra newline

# print a multiplication table with foreach
foreach $i (1,2,3,4,5,6,7,8,9,10,11,12) {
   # print an extra space before numbers under 10 to achieve alignment
   if ($i < 10) { $s = " "; } else { $s = ""; }
   print "$nbr * $s$i = ",$nbr*$i,"\n";
}
print "\n"; # extra newline

# print a multiplication table with while
$i = 1;
while ($i <= 12) {
   # print an extra space before numbers under 10 to achieve alignment
   if ($i < 10) { $s = " "; } else { $s = ""; }
   print "$nbr * $s$i = ",$nbr*$i,"\n";
   $i++;
}


TEST

erikt@stuwww:~$  perl -w 21.pl
Please enter a number: 23
23 *  1 = 23
23 *  2 = 46
23 *  3 = 69
23 *  4 = 92
23 *  5 = 115
23 *  6 = 138
23 *  7 = 161
23 *  8 = 184
23 *  9 = 207
23 * 10 = 230
23 * 11 = 253
23 * 12 = 276

23 *  1 = 23
23 *  2 = 46
23 *  3 = 69
23 *  4 = 92
23 *  5 = 115
23 *  6 = 138
23 *  7 = 161
23 *  8 = 184
23 *  9 = 207
23 * 10 = 230
23 * 11 = 253
23 * 12 = 276

23 *  1 = 23
23 *  2 = 46
23 *  3 = 69
23 *  4 = 92
23 *  5 = 115
23 *  6 = 138
23 *  7 = 161
23 *  8 = 184
23 *  9 = 207
23 * 10 = 230
23 * 11 = 253
23 * 12 = 276