Thank you very much Ikegami.

One last thing, if I want to create 3 sets of 5 integers each from the
+ integer range 1 to 15 then which one is better from randomness angle
+:

1. I shuffle the previously "shuffled" list in each iteration, or
2. I shuffle the "original" list in each iteration.

Here is the code:

Method 1:
my @array=(1..15);
my @shufflednumbers=();

foreach my $i (1..3) {
    @shufflednumbers = shuffle (@array);
    print "@shufflednumbers[0..4]";
    @shufflednumbers=();
}

Method 2:
my @array=(1..15);
my @temp=@array;
my @shufflednumbers=();

foreach my $i (1..3) {
    @shufflednumbers = shuffle (@temp);
    print "@shufflednumbers[0..4]";
    @temp=@shufflednumbers;
    @shufflednumbers=();
}
[download]

Method 1 is fine.

my @array = (1..15);

for (1..3) {
    my @shufflednumbers = (shuffle(@array))[0..4];
    print "@shufflednumbers\n";
}
[download]