The
public Access Specifier
The
public access specifier allows a class to expose its member variables and
member functions to other functions and objects. Any member that is declared
public can be accessed from outside the class.
using System;
namespace ConsoleApplication1
{
class Car
{
//
"CarColor" variable is private, it cannot be accessed outside the
class definition
private string CarColor;
}
class Bike
{
//
"BikeColor" variable is public, it can be accessed outside the class
definition
public string BikeColor;
}
class Program
{
static void Main(string[] args)
{
Car car
= new Car();
car.CarColor = "Red"; // Error:
"CarColor" is inaccessible due to its protection level
Bike bike
= new Bike();
bike.BikeColor = "Red";
Console.ReadLine();
}
}
}
The
private Access Specifier
The
private access specifier allows a class to hide its member variable &
member functions from other class and functions. Therefore, the private member
of a class is not visible outside a class. If a member is declared private,
only the functions of that class can access the member. Even the instance of
the class cannot access its private Members. Therefore, the data is hidden and
cannot be altered any function other than the member functions of the class.
using System;
namespace ConsoleApplication1
{
class Car
{
//
"Model" variable is private, it cannot be accessed outside the class
definition
private string Model;
void Honk()
{
Console.WriteLine("PARRP
PARRP!");
}
}
class Program
{
static void Main(string[] args)
{
Car car
= new Car();
car.Model = "Maruti Swift"; // Error:
"Model" is inaccessible due to its protection level
car.Honk(); // Error: "Honk()" is inaccessible due to its
protection level
Console.ReadLine();
}
}
}
Tips:
When
you do not specify any data member as public, protected, or private,
then the default access specifier for a data member is private. In
the following example, the data member Model is private, even though it has not
been specified explicitly.
class Car
{
string Model;
}
The
protected Access Specifier
This
specifier allows a class to hide its member variables and member functions from
other class objects and functions, except the child class. The protected access
specifier becomes important while implementing inheritance.
using System;
namespace ConsoleApplication1
{
class Car
{
//
"Model" variable is protected, it cannot be accessed outside the
class definition, except the child class
protected string Model;
void Honk()
{
Console.WriteLine("PARRP
PARRP!");
}
}
class Program
{
static void Main(string[] args)
{
Car car
= new Car();
car.Model = "Maruti Swift"; // Error:
"Model" is inaccessible due to its protection level
car.Honk(); // Error: "Honk()" is inaccessible due to its
protection level
Console.ReadLine();
}
}
}
Accessing the protected variable in the child class
using System;
namespace ConsoleApplication2
{
class Car
{
//
"Model" variable is protected, it cannot be accessed outside the
class definition, except the child class
protected string Model;
void Honk()
{
Console.WriteLine("PARRP
PARRP!");
}
}
class Program : Car
{
public void SetModel()
{
Model = "Maruti Swift";
}
public void GetModel()
{
Console.WriteLine(Model);
}
static void Main(string[] args)
{
Car car
= new Car();
car.Model = "Maruti Swift"; // Error:
"Model" is inaccessible due to its protection level
car.Honk(); // Error: "Honk()" is inaccessible due to its
protection level
Program program
= new Program();
program.SetModel();
program.GetModel();
Console.ReadLine();
}
}
}
Tips:
When
you do not specify any data member as public, protected, or private,
then the default access specifier for a data member is private. In
the following example, the data member Honk() is
private, even though it has not been specified explicitly.
class Car
{
void Honk()
{
}
}
The
infernal Access Specifier
The
internal access specifier allows a class to expose its member variables and
member functions to other functions and objects. Any member that is declared
internal can be accessed from any class or method defined within the
application in which the member is defined. When you do not specify any data
member as public, protected or private the default access specifier for a class
is internal.
using System;
namespace ConsoleApplication1
{
class Car
{
//
"CarColor" variable is private, it cannot be accessed outside the
class definition
private string CarColor;
//
"Honk()" is internal, it cannot be accessed outside the class
definition
internal void Honk()
{
Console.WriteLine("PARRP
PARRP!");
}
}
class Bike
{
//
"BikeColor" variable is internal, it can be accessed outside the
class definition
internal string BikeColor;
}
class Program
{
static void Main(string[] args)
{
Car car
= new Car();
car.CarColor = "Red"; // Error:
"CarColor" is inaccessible due to its protection level
car.Honk();
Bike bike
= new Bike();
bike.BikeColor = "Red";
Console.ReadLine();
}
}
}
Tips:
When
you do not specify any data member as public, protected or private the default
access specifier for a class is internal.
The
protected internal Access Specifier
The
type or member can be accessed by any code in the assembly in which it is
declared, or from within a derived class in another assembly. The protected
internal access specifier becomes important while implementing inheritance.
|
Public
|
Public Members are available anywhere.
|
|
Private
|
Private Members are available only within the same class.
|
|
Protected
|
Protected Members are available within the same class and derived class
|
|
Internal
|
Internal Members are available anywhere within the same assembly
|
|
Protected Internal
|
Protected Internal are available anywhere within the same assembly and
derived class in any another assembly.
|
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