In C#, what is the difference between public, private, protected, and having no access modifier?
.net, access-modifiers, asp.net, c#
Solution
Access modifiers
From learn.microsoft.com:
`public`
The type or member can be accessed by any other code in the same assembly or another assembly that references it.
`private`
The type or member can only be accessed by code in the same class or struct.
`protected`
The type or member can only be accessed by code in the same class or struct, or in a derived class.
`private protected` (added in C# 7.2)
The type or member can only be accessed by code in the same class or struct, or in a derived class from the same assembly, but not from another assembly.
`internal`
The type or member can be accessed by any code in the same assembly, but not from another assembly.
`protected internal`
The type or member can be accessed by any code in the same assembly, or by any derived class in another assembly.
When no access modifier is set, a default access modifier is used. So there is always some form of access modifier even if it's not set.
`static` modifier
The static modifier on a class means that the class cannot be instantiated, and that all of its members are static. A static member has one version regardless of how many instances of its enclosing type are created.
A static class is basically the same as a non-static class, but there is one difference: a static class cannot be externally instantiated. In other words, you cannot use the new keyword to create a variable of the class type. Because there is no instance variable, you access the members of a static class by using the class name itself.
However, there is a such thing as a static constructor. Any class can have one of these, including static classes. They cannot be called directly & cannot have parameters (other than any type parameters on the class itself). A static constructor is called automatically to initialize the class before the first instance is created or any static members are referenced. Looks like this:
static class Foo()
{
static Foo()
{
Bar = "fubar";
}
public static string Bar { get; set; }
}
Static classes are often used as services, you can use them like so:
MyStaticClass.ServiceMethod(...);
Problem
All my college years I have been using `public`, and would like to know the difference between `public`, `private`, and `protected`? Also what does `static` do as opposed to having nothing?