Jaspersan has asked for the wisdom of the Perl Monks concerning the following question: 

Ok, how do i reset an array to hold nothing?
#--
@arr; #??
#--
#I make an array like so:
@array=&getarray();
#and i loop through it, and append it to $blah:
foreach $val (@array) {
$blah=$blah.",".$val;
}
#but everytime i do this it appends the new array to the old $blah, i 
+tried $blah;
^jasper <jasper@wintermarket.org>

[download]
Updated by boo_radley : title change

Replies are listed 'Best First'.
(jeffa) Re: Arrays
by jeffa (Bishop) on May 05, 2002 at 22:17 UTC
    You can 'reset' an array like so: 
    @arr = ();

    [download]
    But you don't need to do that to get your code to work: 
    use strict; # ALWAYS!!!

my @array = &getarray();
my $blah;

foreach my $val (@array) {
   $blah .= ",$val";
}
print "$blah\n";

sub getarray {
   return ('a'..'d');
}

    [download]
    Also, don't forget about join which will replace the for loop and concatention for you (and do a much better job anyway): 
    print join(',', getarray()), "\n";

    [download]

    jeffa

    L-LL-L--L-LL-L--L-LL-L--
-R--R-RR-R--R-RR-R--R-RR
B--B--B--B--B--B--B--B--
H---H---H---H---H---H---
(the triplet paradiddle with high-hat)
[reply]
[d/l]
[select]
      my @array = &getarray();

      I tried it out and see that this works, but it doesn't seem to me that it should, since you appear to be storing a reference to the function in the array rather than the list of values returned by the function. Is this just a technique for deferring execution of getarray until the foreach my $val (@array) or is something else going on here?

[reply]
[d/l]
[select]
        No deferrence going on here - &get_array() simple returns an array and not a reference (sub or array). Maybe this code will shed some light: 
        use strict;
use Data::Dumper;

print Dumper get_array();
print Dumper get_array_ref();

print Dumper scalar get_something();
print Dumper get_something();

sub get_array {
   return ('a'..'d');
}

sub get_array_ref {
   return [('a'..'d')];
}

sub get_something {
   return wantarray ? ('a'..'d') : 'scalar';
}

        [download]
        Also check out the difference between a list and an array

        jeffa

        L-LL-L--L-LL-L--L-LL-L--
-R--R-RR-R--R-RR-R--R-RR
B--B--B--B--B--B--B--B--
H---H---H---H---H---H---
(the triplet paradiddle with high-hat)
[reply]
[d/l]
        That line just calls the sub and puts whatever is returned into @array. If you wanted to store a reference to a sub you would do this: 
        my $subref = \&getarray;

        [download]
[reply]
[d/l]

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