my @interfaceref_array;

for my $name (@list_of_junk) {

    my $hash_ref = {  # curly brackets enclose
        junk_name => $name,  # quotes not needed
        two       => result_of_function($name),
        };

    do_some_stuff();

    $hash_ref->{three} = "toilet";  # quotes needed for value

    push @interfaceref_array, $hash_ref;

    }

##</code><code>##

my @interfaceref_array;

for my $name (@list_of_junk) {

    my %hash = (  # parentheses enclose
        junk_name => $name,
        two       => result_of_function($name),
        );

    do_some_stuff();

    $hash{three} = "toilet";

    push @interfaceref_array, \%hash;

    }