private (C# Reference)

 

Updated: July 20, 2015

For the latest documentation on Visual Studio 2017 RC, see Visual Studio 2017 RC Documentation.

The private keyword is a member access modifier. Private access is the least permissive access level. Private members are accessible only within the body of the class or the struct in which they are declared, as in this example:

class Employee  
{  
    private int i;  
    double d;   // private access by default  
}  

Nested types in the same body can also access those private members.

It is a compile-time error to reference a private member outside the class or the struct in which it is declared.

For a comparison of private with the other access modifiers, see Accessibility Levels and Access Modifiers.

In this example, the Employee class contains two private data members, name and salary. As private members, they cannot be accessed except by member methods. Public methods named GetName and Salary are added to allow controlled access to the private members. The name member is accessed by way of a public method, and the salary member is accessed by way of a public read-only property. (See Properties for more information.)

    class Employee2
    {
        private string name = "FirstName, LastName";
        private double salary = 100.0;

        public string GetName()
        {
            return name;
        }

        public double Salary
        {
            get { return salary; }
        }
    }

    class PrivateTest
    {
        static void Main()
        {
            Employee2 e = new Employee2();

            // The data members are inaccessible (private), so
            // they can't be accessed like this:
            //    string n = e.name;
            //    double s = e.salary;

            // 'name' is indirectly accessed via method:
            string n = e.GetName();

            // 'salary' is indirectly accessed via property
            double s = e.Salary;
        }
    }

For more information, see the C# Language Specification. The language specification is the definitive source for C# syntax and usage.

C# Reference
C# Programming Guide
C# Keywords
Access Modifiers
Accessibility Levels
Modifiers
public
protected
internal

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