Delete returns the deleted value*s* (plural) of a slice and you didn't test a slice. ¹

Exists returns an (informal) Boolean (1 or dualvar ""/0) for a hash entry, and logically should also return a list of booleans in case of a slice.

Cheers Rolf

(addicted to the Perl Programming Language :)
see Wikisyntax for the Monastery

Edit

¹) From the docs of delete I already linked to 

my %hash = (foo => 11, bar => 22, baz => 33);
my $scalar = delete $hash{foo};         # $scalar is 11
$scalar = delete @hash{qw(foo bar)}; # $scalar is 22
my @array  = delete @hash{qw(foo baz)}; # @array  is (undef,33) <--- H
+ERE

[download]

In reply to Re^4: Why doesn't exist work with hash slices? by LanX
in thread Why doesn't exist work with hash slices? by Anonymous Monk

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.