[2.0] slight confusion between "Object" vs "object"

[bnathvbdotnet]

while typing using VS 2005, C#, intellisense shows "Object" and "object" .

what is the difference. The help shows both are Object class . then why Uppercase Object and lower case object is displayed by intellisense?

nath

[jmcilhinney]

"Object" is a .NET type and "object" is a C# data type. With an upper case "O" it is actually System.Object but without the qualifying namespace. If you remove the "using System;" line from the top of the code file you'll see that you cannot use "Object" anymore. With a lower case "o" it is the the in-built C# object data type. Most languages have in-built data types for the most commonly used types. C# has a number of in-built data types and below is a table of the .NET type that is used to implement implement some of them.

C# data type    .NET type

object          System.Object
bool            System.Boolean
int             System.Int32
float           System.Single
double          System.Double
decimal         System.Decimal
string          System.String

Note that the .NET types turn a light aqua-ish colour in the IDE and the C# data types, like all language key words, turn a bright blue colour.

[bnathvbdotnet]

jm,

can we say object (lower case o which is in-built C# object data type) as an alias for System.Object class?

I meant object (lower case) is alias of Object?

thanks
nath

[jmcilhinney]

All C# data types are implemented using .NET types, so an object and an Object are essentially the same thing. VB.NET has its own data types too. A VB.NET Integer and a C# int are both implemented using the System.In32 structure. I suggest that you start making use of your F1 key. Had you typed a line like:

object o;

then placed your cursor in the "object" word and pressed F1 it would have taken you straight to the help topic for the object data type, which says:

The object type is an alias for Object in the .NET Framework.

where "Object" is a link to the topic for the System.Object class.