G'day Sami_R,

"... set hash values to '-', is there any simplest way of implementing this, please."

You can assign to multiple keys at the same time using a hash slice (see "perldata: Slices"). You can assign multiple, identical values using the repetition operator (see "perlop: Multiplicative Operators").

As already pointed out, information from you is missing. The following code should give you an idea of a technique you might employ; of course, it's impossible to even suggest implementation details.

$ perl -e '
    my @hashes;
    my @days = ([1,2,3], [], [], [4,5,6]);
    for (0 .. $#days) {
        my %x = (day => 1+$_);
        @x{qw{bal pay tot}}
            = @{$days[$_]} ? @{$days[$_]} : ("-") x 3;
        push @hashes, \%x;
    }
    use Data::Dump;
    dd \@hashes;
'
[
  { bal => 1, day => 1, pay => 2, tot => 3 },
  { bal => "-", day => 2, pay => "-", tot => "-" },
  { bal => "-", day => 3, pay => "-", tot => "-" },
  { bal => 4, day => 4, pay => 5, tot => 6 },
]
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