Question

I read Stack Overflow question How do I convert a binary string to a number in Perl? on how to convert binary integers to decimal or vice versa in Perl. But how do I do this for float as well?

For example, conversion from 5.375 to 101.011 and vice versa.

Answer 1

sub number_to_binary_string {
    my $in = shift;
    my $sign = $in < 0 and $in = abs $in;
    my $out = sprintf "%b.", int $in;
    substr $out, 0, 0, '-' if $sign;
    $in -= int $in;
    do {
        if ($in >= .5) {
            $out .= '1';
            $in -= .5;
        }
        else {
            $out .= '0';
        }
        $in *= 2;
    } while $in > 0;
    return $out;
}

sub binary_string_to_number {
    my $in = shift;
    my ($int,$frac) = split /\./, $in;
    my $sign = $int =~ s/^-//;
    my $out = oct "0b$int";
    my $mult = 1;
    for my $digit (split //, $frac) {
        $mult *= .5;
        $out += $mult * $digit;
    }
    $out = -$out if $sign;
    return $out;
}