How should I parse Infinity with Double?

Question

If I try

Double.Parse("Infinity")

I get

Double.Parse("Infinity") threw an exception of type 'System.FormatException'

Why? And what should I do if I want to parse it anyway and get a Double with the value Infinity?

Answer 1

I just found this out:

Decimal.Parse("Infinity", System.Globalization.CultureInfo.InvariantCulture);

will work and return a double with the value +Infinity.

The reason it did not work is that I am not, I think, automatically in the InvariantCulture but perhaps in the de-DE culture which does not handle the exact string "Infinity". (Perhaps it would handle some other string.)

Answer 2

All the below parsing are valid, since your system settings are different is causing the issue. As dontomaso had answered above just need to add the Invariant Culture.

Double.Parse("NaN", System.Globalization.CultureInfo.InvariantCulture)
Double.Parse("-Infinity", System.Globalization.CultureInfo.InvariantCulture)
Double.Parse("Infinity", System.Globalization.CultureInfo.InvariantCulture)