Quick question about arrays and MonoDevelop

I made a boolean array (using C#) in my game manager class, but when I write code to access it, “.Length” doesn’t appear in the MonoDevelop drop-down list of code options.

I can actually use “.Length” just fine - it returns the correct value every time. But I was wondering, why doesn’t it appear as an option?

It’s not a big deal, I’m just curious as to what the reason might be, since “.Length” does appear for other arrays in the class.

Thing like that, I had too, locate in a menu Project → Assembly options → Build → general and select target framework to .net 3.5/mono