In your sample code int is not doing anything. Indeed, if you actually run it with the strictures you show you will get the warning 'Useless use of int in void context at ...'.

Don't use &subName to call a sub. Use subName () instead. The &subName version of the call has some potentially nasty habits.

the following cleaned up sample may help:

use strict;
use warnings;


my @list;

while (<DATA>) {
        chomp;
        push (@list, $_);
}

comp ();


sub comp {
    printf "%-12s%-12s%-12s%-12s\n", ('    +v', '    -v') x 2;
    foreach my $element (map int, @list) {
        my $negative = ~$element;
        printf "%11d %11d %#11.8b %#11.8b\n",
            $element, $negative, 0xFF & $element, 0xFF & $negative;
    }
}


__DATA__
1
2
10
-1
-2
-10
123456
-123456
255
256

[download]

Prints:

    +v          -v          +v          -v      
          1          -2  0b00000001  0b11111110
          2          -3  0b00000010  0b11111101
         10         -11  0b00001010  0b11110101
         -1           0  0b11111111  0b00000000
         -2           1  0b11111110  0b00000001
        -10           9  0b11110110  0b00001001
     123456     -123457  0b01000000  0b10111111
    -123456      123455  0b11000000  0b00111111
        255        -256  0b11111111  0b00000000
        256        -257  0b00000000  0b11111111

[download]

Note the use of map in the for loop to apply int to each of the array elements.

Update fixed stupid paste error (thanks toolic)!

True laziness is hard work

In reply to Re: bit selections by GrandFather
in thread bit selections by biohisham

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.