C# – ‘namespace’ but is used like a ‘type’

cclassnamespaces

This is my program the class uses it is called Time2
I have the reference added to TimeTest
I keep getting the Error 'Time2' is a 'namespace' but is used like a 'type'

Could someone please tell me what this error is and how to fix it?

namespace TimeTest
{
  class TimeTest
  {
    static void Main(string[] args)
    {
        Time2 t1 = new Time2();
    }
  }
}

Best Answer

I suspect you've got the same problem at least twice.

Here:

namespace TimeTest
{
    class TimeTest
    {
}

... you're declaring a type with the same name as the namespace it's in. Don't do that.

Now you apparently have the same problem with Time2. I suspect if you add:

using Time2;

to your list of using directives, your code will compile. But please, please, please fix the bigger problem: the problematic choice of names. (Follow the link above to find out more details of why it's a bad idea.)

(Additionally, unless you're really interested in writing time-based types, I'd advise you not to do so... and I say that as someone who does do exactly that. Use the built-in capabilities, or a third party library such as, um, mine. Working with dates and times correctly is surprisingly hairy. :)

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There is actually a (subtle) difference between the two. Imagine you have the following code in File1.cs:

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This changes if you put the using inside your namespace declaration, as follows:

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Some would argue that Math might be a bad name for a user-defined class, since there's already one in System; the point here is just that there is a difference, and it affects the maintainability of your code.

It's also interesting to note what happens if Foo is in namespace Outer, rather than Outer.Inner. In that case, adding Outer.Math in File2 breaks File1 regardless of where the using goes. This implies that the compiler searches the innermost enclosing namespace before it looks at any using directive.

Best Answer

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