What is the default access modifier for classes, methods, members, constructors, delegates and interfaces?
Answer
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.)
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