Beefy Boxes and Bandwidth Generously Provided by pair Networks
We don't bite newbies here... much
 
PerlMonks  

Comment on

( #3333=superdoc: print w/ replies, xml ) Need Help??
> my @uniq = keys %{ {%hash1, %hash2} };

From inside out:

- First the two hashes are flattened to lists, which are combined to a long list.

- Building a new (anonymous) hashref will eliminate duplicated entries from that hash ╣

- To be able to extract▓ the keys you still need to dereference this ano-hashref with %{..}.

step by step:

DB<111> %hash1= (a=>1,b=>2) => ("a", 1, "b", 2) DB<112> %hash2= (a=>1,c=>3) => ("a", 1, "c", 3) DB<113> (%hash1, %hash2) => ("a", 1, "b", 2, "c", 3, "a", 1) DB<115> + {%hash1, %hash2} => { a => 1, b => 2, c => 3 } DB<117> %{ {%hash1, %hash2} } => ("c", 3, "a", 1, "b", 2) DB<118> keys %{ {%hash1, %hash2} } => ("c", "a", "b")

Cheers Rolf

UPDATES:

╣) because repeated keys will be overwritten.

▓) at least with older perl-versions, see Athanasius' remark


In reply to Re: Syntax explanation required by LanX
in thread Syntax explanation required by ghosh123

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!
  • 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, 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, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • Outside of code tags, you may need to use entities for some characters:
            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.
  • Log In?
    Username:
    Password:

    What's my password?
    Create A New User
    Chatterbox?
    and the web crawler heard nothing...

    How do I use this? | Other CB clients
    Other Users?
    Others musing on the Monastery: (10)
    As of 2014-12-21 12:18 GMT
    Sections?
    Information?
    Find Nodes?
    Leftovers?
      Voting Booth?

      Is guessing a good strategy for surviving in the IT business?





      Results (104 votes), past polls