Let's say you have an array of data that contains empty lines, like this.

Hello

World


How
are

you

The following markup can be used to remove the empty lines from the array. The \S regular expression means "anything except for a whitespace". It may also be noteworthy that \s means "whitespace", thus \S is the opposite of \s.

@array = grep /\S/, @array;

Which will result in the array having no empty lines, like this.

Hello
World
How
are
you

Looping through array

If you are looping through the array, something like this should get the job done.

foreach my $line (@array) {

  $line =~ s|^\s*$||g;

}