Re^2: Good Perl book?

[Athanasius]

This is actually pretty close to what you wanted. Un-comment use warnings and the resulting message will help to identify the problem:

Use of uninitialized value in concatenation (.) or string at first.pl 
+line 5.

The problem loop is:

foreach my $num (@arr) {
        print "Index is: $num. Value is: $arr[$num] ";
}

and as the output shows, the loop value is always one greater than the index. That’s because arrays in Perl (as in C) are subscripted starting from zero, so $arr[1] is actually the second element. The loop is easily fixed:

foreach my $num (@arr) {
        print "Index is: $num. Value is: $arr[$num - 1] ";    # Subtra
+ct 1 from the index
}

Also un-comment use strict, and you’ll see that the only error message pertains to this line:

for($num = 0; $num<= $#arr;$num++) {

Declare $num as a lexical variable:

for (my $num = 0; ...

and strict is happy.

Hope that helps,

[Anonymous Monk]

Thank you for your patience and guidance. It was stupid of me to comment it out. Perl and perlmonks are awesome. Respect.