Detecting +/-1.#J

[george7378]

Hi everyone,

How do I detect when the answer to a sum is infinity? I need to implement it into the following code:

if (Number == (Infinity))
    MessageBox(hwnd, "Enter a number above zero.", "Error", MB_OK);
    break;

It is a division sum.

Thanks.

[EVOEx]

See fpclassify or isinf ;-). The latter does just that.

[brewbuck]

Why not check if the denominator is zero before dividing?

[george7378]

Thanks.

I tried the check for 0, but it didn't seem to work for division sums.

Please could you show me how to use the isinf() operation?

Thanks.

[Brafil]

Well, look up a reference for that - you should really have one. Or use an online one, there are plenty. Basically, it's very simple: if (isinf(num)) ...;