What is the difference between the 'namespace' and the 'using' keywords in C#?

Question

I'm new to C# and I don't fully understand what a namespace is, and what the using -keyword does. I'd appreciate it if someone could explain the difference. From my guess, using is similar to #include in C++.

If that's the case, what is a namespace for? The only exposure I've had to namespaces in C++, was when using using namespace std; , which just allowed me to forgo the std:: in my function calls.

Answer 1

The namespace - statement declares a namespace of your own; A set of "bundled classes" if you like. You can have very different classes in a name space, and you can also create sub-namespaces.

Using the namespace statement will therefor, implicitly make sure you can access other classes in the same namespace . You do not need to make explicit references within the same namespace.

Read more on namespaces in C# here .

The using directive is used to use a namespace in your code, without explicitly referencing to a namespace. This is of course useful when using a namespace more than once in a class. The directive does not change the state or status of the class, as the namespace statement does.

Read more on the using directive in C# here .

There is also much more things you can do with the using keyword...

Answer 2

Quick dirty answer -

namespace - is a collection of classes that you are naming and filling with classes yourself

using - brings in a namespace(collection of classes) to be used

For a cleaner understanding of the parts of a C# program - https://www.tutorialspoint.com/What-are-the-main-parts-of-a-Chash-program

Answer 3

you are almost correct. To find out more about namespace and using refer here
Since you are new to C# i recommend you to go through the microsoft c# and.Net documentation if you have any doubts. Hope this helps:)