C# : Access modifiers : Part 19

There are 5 types of access modifiers in c#

• Public : Accessible anywhere no restriction.
• Private : Accessible only in the containing type.
• Protected : Within containing types and the types derived from containing types.
• Internal : Accessible anywhere in the containing assembly, not accessible in other assembly even after adding reference.
• Protected Internal : In containing assembly and accessible within a derived class from any other assembly.

Containing type mostly refers to class

Access Modifier : Public

• As you can see in the image(1) below that Marks property is not accessible when instance of student class is created, all other public properties are accessible

image(1)


Access Modifier : Private

• As seen in image(1) above the property Mark is not accessible because it is private, so it is not accessible outside the containing type, i.e. class
• Where as private property are easily accessible within the containing type, i.e. within the class
• In figure below image(2) Marks field is accessible as it is in the same class.

image(2)


Access Modifier : Protected

• The properties with protected access modifiers are accessible in same class/containing types and from the type derived from the containing types.
• As seen in image(3) below only DemoFunction method is accessible as it is public
image(3)


• In image(4) below the instance of Student class is created, where only public property Surname is accessible
image(4)


• In image(5) the StudentDetils class inherited from Student class, so now if the instance of StudentDetails is created the protected property Class will be accessible
image(5)


Access Modifier : Internal
• The property / method / class declared as internal will be only accessible from anywhere in the same assembly / (DLL) / same project.
• If the reference of the project is given to another project and if tried to access the property which is marked as internal than it willl throw compile time error

Access Modifier : Internal Protected
• The properties marked as internal protected are accessible anywhere in the same assembly / (DLL) / same project.
• They are also accessible from the derived class from any other assembly.