Access Modifiers in C#

Access Modifiers

This article explains access modifiers and their functionality, along with how they differ from each other and what the basics of all these are.

I'll include all 4 access modifiers in this article.

Access Modifiers in C#

  • By default, data and methods defined in a class can only be used inside that class itself.
  • We must choose to expose them.
  • Access modifiers let you specify how programs that use your classes can access their data and methods.

Class Access Modifiers | C#

I will explain this with an example.

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

 

namespace Hello_Word

{

    class Program

    {

           static void Main(string[] args)

          public int Value;

          // public access modifier

          private string Message;

          // private access modifier

          protected void function();

          // protected access modifier

    }

}

We can use any of the class modifiers in our class but each of these modifiers work differently.

Modifiers | Types

Modifiers

Public

The public modifier specifies that the class's values and attributes can be easily accessed by other objects.

Private

The private access modifier is for when the functionality of an attribute of that class can be only used within that class only.

Protected

  • It is used where the class member can only be accessed within the same class.
  • Inherited class of that class (child/subclass)

Internal

  • It is the advanced functionality of C# 5.0 or above.
  • In this modifier the class member can be accessed by any class in the same assembly.
  • A package of code like a library or other program.

Example

There are 2 parts in this code, the first part represents construction building and access modifier definitions. In the second code there is a calling of the access modifiers functionalities.

Part: 1 | Code

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

 

namespace Hello_Word

{

    class Book

    {

        // access modifier- PUBLIC

        public string Name;

        public decimal Price;

        public string Description;

        // access modifier- PRIVATE

        private decimal discount;

        // public constructer

        public Book(string bookName, decimal price)      

        {

            Name = bookName;

            Price = price;

            discount = 0.0m;

        }

    }

}


Part: 2 | Code

class Program

{

    static void Main(string[] args)

    {

        Book b1 = new Book("Black Book", 1050.00m);

        Book b2 = new Book("Complete Refrence", 1250.00m);

        string str = b1.Name;

    }
}

When you do try to define b1.discount then there will be no option in the list as:

discount

It only shows the list of members of that class declared under Public access modifier.

Public access modifier

But if you do try to declare it then it will show an error like this:

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

 

namespace Hello_Word

{

    class Program

    {

        static void Main(string[] args)

        {

            Book b1 = new Book("Black Book", 1050.00m);

            Book b2 = new Book("Complete Refrence", 1250.00m);

            string str = b1.Name;

            decimal dsc = b2.discount;

        }

     }

}

// We can not directly use discount in our next file, because it is defined under a private class, we didn't get the options from the list but if we do try to do so, it will surely show an error as in the following:

"Inaccessible due to private modifier"

Inaccessible due to private modifier

The same in the case of a protected modifier, if you try to access its properties it will again show the same message:

message