Public And Private

Private properties and functions can be accessed or modified only in the class body.

Public members can be accessed or modified anywhere - class body, main function, other function.

It can be understood via the following code:

using System; namespace ConsoleApp1 { class Person { // set default value for id private string id = "1"; public string name; public int age; public void printData() { Console.WriteLine("Name: " + name); Console.WriteLine("Age: " + age); Console.WriteLine("Id: " + id); } } class Program { static void Main(string[] args) { Person personObject = new Person(); personObject.name = "John"; personObject.age = 20; // personObject.id = "new_id"; personObject.printData(); } } }

Output:

Name: John Age: 20 Id: 1

There are a couple of things to notice about the private property id and the public properties name and age:

• Both public and private properties can be accessed/modified in the class body: for public properties - lines 15 and 16, for private properties - line 17.
• Outside the Person class body (like the Main function) only public properties can be accessed/modified - lines 27 and 28.
• If we uncomment line 29 the code will not compile. Because a private member (id in this case) cannot be accessed/modified outside the Person class body.