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declare @A as float;
declare @B as float;
declare @C as float;

set @A = 0.0;
set @B = -1.0;
set @C = @A * @B;

print @C;

$A = -1.0 * 0.0;
echo $A . "\n";

OriginalGriff wrote:

Being annoyingly boring:

double a = -0.0;
Console.WriteLine("a = {0}, 1.0/a = {1}", a, 1.0 / a);
double b = double.Parse("-0.0");
Console.WriteLine("b = {0}, 1.0/b = {1}", b, 1.0 / b);
byte[] abytes = BitConverter.GetBytes(a);
Console.WriteLine("a bytes=" + string.Join(",", abytes.Select(z => z.ToString("X2"))));
byte[] bbytes = BitConverter.GetBytes(b);
Console.WriteLine("b bytes=" + string.Join(",", bbytes.Select(z => z.ToString("X2"))));

a = 0, 1.0/a = -Infinity
b = 0, 1.0/b = Infinity
a bytes=00,00,00,00,00,00,00,80
b bytes=00,00,00,00,00,00,00,00

static void Main(string[] args)
{
    double a = Math.Ceiling(-0.1);
    double b = 1 * 0;
    double c = -1 * 0;
    Console.WriteLine("a = Math.Ceiling(-0.1), a=" + a.ToString());

    byte[] bytes;
    bytes = BitConverter.GetBytes(a);
    Console.WriteLine("Bytes of a:");
    Console.WriteLine(BitConverter.ToString(bytes));

    Console.WriteLine("b = 1 * 0, b=" + b.ToString());
    bytes = BitConverter.GetBytes(b);
    Console.WriteLine("Bytes of b:");
    Console.WriteLine(BitConverter.ToString(bytes));

    Console.WriteLine("c = -1 * 0, c=" + c.ToString());
    bytes = BitConverter.GetBytes(c);
    Console.WriteLine("Bytes of c:");
    Console.WriteLine(BitConverter.ToString(bytes));
}

a = Math.Ceiling(-0.1), a=0
Bytes of a:
00-00-00-00-00-00-00-80
b = 1 * 0, b=0
Bytes of b:
00-00-00-00-00-00-00-00
c = -1 * 0, c=0
Bytes of c:
00-00-00-00-00-00-00-00

Marc Clifton wrote:

Anyways, I found that weird / interesting. How can 0 be negative?

Jochen Arndt wrote:

but not the signbit - C++ Reference[^]?

Marc Clifton wrote:

How can 0 be negative?

Sander Rossel wrote:

Please stop belittling me.

patbob wrote:

Of course, with IEEE floating point, -0.0 is representable, but allowing it would be inconsistent, and very, very confusing.