curious declaration

[dady_fat]

Hello.
I've seen in a Microsoft Workshop a declaration:
decimal? averagePriceInRange = 0;
I've searched for andwers but I couldn't find what the question mark (?) is for.
Any info is appreciate.

Thanks.

[Mutant_Fruit]

It's a nullable struct. Exactly the same as writing: Nullable<decimal>

http://msdn.microsoft.com/en-us/library/b3h38hb0.aspx

[dady_fat]

Many thanks.