Re: Decimal to Binary conversion

[Casey West]

On Tue, Apr 17, 2001 at 03:53:39PM -0500, Gray, Brad D wrote:
: Hi,
: 
: Is there a way to convert two numbers from decimal to binary, and AND them
: together, and convert the result back to decimal?

It is actually much, much easier than that Brad.  Perl has a bitwise
AND operator ( see perlop ):

  my $num1 = 5;
  my $num2 = 6;

  my $result = $num1 & $num2;

Now, if you really want your first two numbers in binary form, you can
try something along these lines:

  print &to_binary( $_ )."\n" foreach @ARGV;

  sub to_binary($;$) {
    my $num  = int shift;
    my $pad  = shift || 8;
    my $bin  = '';
    my $top  = 1;
       $top *= 2 until $top >= $num;

    while ( $top >= 1 ) {
      if ( $num >= $top ) {
        $bin .= 1;
        $num -= $top;
      } else {
        $bin .= 0;
      }
    } continue {
      $top /= 2;
    }
    return sprintf "%0${pad}d", $bin;
  }

Enjoy!

-- 
Casey West