Beefy Boxes and Bandwidth Generously Provided by pair Networks
Perl: the Markov chain saw

Comment on

( #3333=superdoc: print w/ replies, xml ) Need Help??

To supplement the answer by LanX, there are two ways to fill an array or hash: Either you initialize it with all values at once or you insert values one at a time. You seem to mix up these two methods. Here is how both work for arrays and hashes:

# initialize an array at once with 3 scalars, two array pointers and o +ne hash pointer: @array= (1,2,3,\@anotherarray,[1,2],{1=>15}); # initialize a hash at once with three keys. Data is one scalar, one h +ash pointer and one array pointer %hash= (1=>15, 7=>{5=>4}, 2=>[1,2,3]);

As you can see initializing at once is not complicated, you just have to remember that hash and array are both initialized with an array constant that uses (), but constant array pointers are specified with [] and constant hash pointers are specified with {}. Also any old values are completely erased so this doesn't work when you want to add values one by one

Inserting values one at a time (mostly in a loop) on the other hand uses the same "interface" as any normal array or hash operation, so:

foreach ... { $array[$i][$j]= $value; # or push( @{$array[$i]}, $value); $hash{$i}{$j}= $value; }

Since only one value inside the array or hash is changed or added and all other values remain, this works very well in a loop

In reply to Re: Hashes... Light switch isn't coming on by jethro
in thread Hashes... Light switch isn't coming on by agentorange

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
  • 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.
  • Log In?

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

    How do I use this? | Other CB clients
    Other Users?
    Others browsing the Monastery: (11)
    As of 2015-10-07 17:26 GMT
    Find Nodes?
      Voting Booth?

      Does Humor Belong in Programming?

      Results (194 votes), past polls