What are the default access modifiers in C#?
The default access for everything in C# is "the most restricted access you could declare for that member".
So for example:
namespace MyCompany
{
class Outer
{
void Foo() {}
class Inner {}
}
}
is equivalent to
namespace MyCompany
{
internal class Outer
{
private void Foo() {}
private class Inner {}
}
}
The one sort of exception to this is making one part of a property (usually the setter) more restricted than the declared accessibility of the property itself:
public string Name
{
get { ... }
private set { ... } // This isn't the default, have to do it explicitly
}
This is what the C# 3.0 specification has to say (section 3.5.1):
Depending on the context in which a member declaration takes place, only certain types of declared accessibility are permitted. Furthermore, when a member declaration does not include any access modifiers, the context in which the declaration takes place determines the default declared accessibility.
- Namespaces implicitly have public declared accessibility. No access modifiers are allowed on namespace declarations.
- Types declared in compilation units or namespaces can have public or internal declared accessibility and default to internal declared accessibility.
- Class members can have any of the five kinds of declared accessibility and default to private declared accessibility. (Note that a type declared as a member of a class can have any of the five kinds of declared accessibility, whereas a type declared as a member of a namespace can have only public or internal declared accessibility.)
- Struct members can have public, internal, or private declared accessibility and default to private declared accessibility because structs are implicitly sealed. Struct members introduced in a struct (that is, not inherited by that struct) cannot have protected or protected internal declared accessibility. (Note that a type declared as a member of a struct can have public, internal, or private declared accessibility, whereas a type declared as a member of a namespace can have only public or internal declared accessibility.)
- Interface members implicitly have public declared accessibility. No access modifiers are allowed on interface member declarations.
- Enumeration members implicitly have public declared accessibility. No access modifiers are allowed on enumeration member declarations.
(Note that nested types would come under the "class members" or "struct members" parts - and therefore default to private visibility.)
top level class: internal
method: private
members (unless an interface or enum): private (including nested classes)
members (of interface or enum): public
constructor: private (note that if no constructor is explicitly defined, a public default constructor will be automatically defined)
delegate: internal
interface: internal
explicitly implemented interface member: public!