Question

I have seen that in some cases we use following syntax format in c#,

[something]
void methodM(){

}

Example :

[MethodImpl(MethodImplOptions.Synchronized)]
public void SomeMethod() {/* code */}

[WebMethod]
public void MyWebMethod(){/* code */}

How this works at the compilation?

Answer 1

Explanation

Those are attributes or annotations. They are kind of metadata for the member they are placed on.

For example, using MethodImpl attribute, you can specify the details of how a method is implemented. And using WebMethod attribute, you mark that method as a web service method.

Further reading:

Attributes (C# Programming Guide)

Attributes in C#