To reuse getCreditAccounts(), you'd have to first rewrite the method to return array ref, and not a copy of the array you are attempting to ultimately change. 
# private getCreditAccounts
sub getCreditAccounts {
    caller(0) eq __PACKAGE__ || confess "getCreditAccounts is private"
+;
    my $closure = shift;
    my @accounts = @{ &{$closure}( "CREDITACCOUNTS" ) };
    return @accounts;
}

# working on a copy of the original array...
my @anotherArray = $obj->getCreditAccounts();
push @anotherArray, "Data";

[download]
From there, you could possibly do something like 
# private getCreditAccounts
# now returning reference to the original array
sub getCreditAccounts {
    caller(0) eq __PACKAGE__ || confess "getCreditAccounts is private"
+;
    my $closure = shift;
    return &{$closure}( "CREDITACCOUNTS" ) };
}

# public to add accounts to the creditaccounts
sub addCreditAccount {
    my $closure  = shift;
    my $account = shift;
    push @{ $closure->getCreditAccounts() }, $account;
}

[download]


_____________________
"We've all heard that a million monkeys banging on a million typewriters will eventually reproduce
the entire works of Shakespeare. Now, thanks to the Internet, we know this is not true."

Robert Wilensky, University of California

In reply to Re: composite pattern, best practice, pushing into an array in a hash, reusing the get array method by vladb
in thread composite pattern, best practice, pushing into an array in a hash, reusing the get array method by gargle

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.