Default Class Accessibility in C#

Question

by default is a class:

1. private ?
2. internal ?
3. sealed ?

Answer 1

The default for non-nested types is internal. The default for nested types is private. In both cases the default (for classes) is unsealed.

The general rule for all members is that if you don't specify an access modifier, it's as private as it can be. The single exception for this is properties which can make one part (i.e. the getter or the setter) more private than the overall property by specifying an access modifier, e.g.

public string Foo { get; private set; }

Answer 2

internal

see: http://msdn.microsoft.com/en-us/library/ms173121.aspx