What are the differences between C# namespace declaration with semicolon and curly braces?

Question

I have noticed two distinct methods of namespace declaration in C#.

namespace FirstProgram;

and

namespace FirstProgram {...}

I am looking for information on the key distinctions and purposes of the two types of namespace declarations in C#.

Example: with a semicolon ";"

namespace FirstProgram; // Why use semecolon (;)?

class Program
{
    //fields and methods
}

and

Example: with curly braces "{...}"

namespace FirstProgram // What is the difference in using curly braces ({...})?
{ 
    class Program
    {
        //fields and methods
    }
}

Answer 1

Namespaces without the curly braces are called file-scoped namespaces and were introduced with C# 10 . Usually, a C# file contains only a single namespace. If the File-scoped namespaces are used, one level of nesting can be eliminated.

The only difference is, that when using file-scoped namespaces , you can't have multiple namespaces inside a single file.

Answer 2

The form without the braces, "file scoped namespace declarations" , is a syntax sugar feature introduced in C# 10 . They are equivalent.