Is it possible to compare a double with a float in c# without casting to
one of the types first?

It appears you cannot...


float num = 1.545f;
double dnum = 1.545;

if (dnum == num)
{
Console.WriteLine("You can");
}
else
{
Console.WriteLine("You cant");
}

Andrew,

No, you can not. It's like apples and oranges, you can't compare. You
have to convert one to the other before you compare.

Hope this helps.

--
- Nicholas Paldino [.NET/C# MVP]
- (E-Mail Removed)

"Andrew Murray" <(E-Mail Removed)> wrote in message
news:d14fke$1rk$(E-Mail Removed)...
> Is it possible to compare a double with a float in c# without casting to
> one of the types first?
>
> It appears you cannot...
>
>
> float num = 1.545f;
> double dnum = 1.545;
>
> if (dnum == num)
> {
> Console.WriteLine("You can");
> }
> else
> {
> Console.WriteLine("You cant");
> }

In addition to what Nicholas said, it almost never makes
sense to compare floating point variables for equality.
Instead, check if the difference is smaller than some value,
e.g.:

if (Math.Abs(num1 - num2) < 0.001)
....

- Magnus

"Andrew Murray" <(E-Mail Removed)> wrote in message
news:d14fke$1rk$(E-Mail Removed)...
> Is it possible to compare a double with a float in c# without casting to
> one of the types first?
>
> It appears you cannot...
>
>
> float num = 1.545f;
> double dnum = 1.545;
>
> if (dnum == num)
> {
> Console.WriteLine("You can");
> }
> else
> {
> Console.WriteLine("You cant");
> }

"Magnus Krisell" <net.magnuskrisell@mail> wrote in message
news:(E-Mail Removed)...
> In addition to what Nicholas said, it almost never makes
> sense to compare floating point variables for equality.
> Instead, check if the difference is smaller than some value,
> e.g.:
>
> if (Math.Abs(num1 - num2) < 0.001)

To refine this, the threshold for equality should be related to the size of
the numbers being compared. If num1 is .00002 and num2 is .001, they're
equal to zero significant digits, but they will satisfy the condition above.
If num1 is 6.123456 * 10**23 and num2 is 6.123457 * 10**23, they're equal to
6 significant digits, but don't satisfy it.