Clever Geek Handbook

How to determine which value types are initialized by the CLR

This applies to C # and the .NET Framework.

Your best bet is not to initialize the following types in the .NET framework because the CLR will initialize them for you:

Int, bool, etc.

and the same for setting the object to null (I believe).

For example, you don't need to do this, and in fact it's a performance hit (falls in the bucket or not):

int Myvar = 0;

You just need int Myvar;

this. The CLR initializes it to int.

I obviously just "know" from programming that by default int is set to 0 and bool is false.

And also setting the object to null, since the CLR does it for you. But how can you determine what these primitive types are about. I tried opening Reflector to take a look at int32 and bool, but couldn't figure out how they are initialized by default.

I looked at msdn and I can't see it either. Maybe I just missed it.

+1


source to share


8 answers


If you want a table, MSDN is your friend: Default Values ​​Table (C # link)



+2


source


You need a list like this



+2


source


You can easily create a program that prints by default (T) for all T.

+1


source


Everything is basically zeroed out, so just from there from there. Int / Double / etc 0. String or other structure, probably String.Empty, Guid.Empty, etc. Bool, false (0 in other languages.)

It's pretty intuitive.

0


source


For C #, here is a list of all value types - click the link for each to see what's the default:

Value type table (C # reference)

0


source


It might be a long shot, but I would say that

default( T )

will give you fairly accurate results.

0


source


Try debugging your application and check what the initial value was before you changed it. There might be a better answer, but in order to close this thread I am just posting a quick and dirty solution.


        static void Main(string[] args)
        {
            int iTest;
            string sTest;
            double dTest;
            bool bTest;
            float fTest;

            // stop debugger here
            Console.WriteLine();

            iTest = 0;
            sTest = "";
            dTest = 0.0;
            bTest = false;
            fTest = 0;
        }
0


source


http://www.codeproject.com/KB/dotnet/DontInitializeVariables.aspx

Here we go. Simple: value types are initialized to 0 and reference types are initialized to zero

0


source






More articles:


All Articles