C# Properties

C# Properties (Get and Set)

Before we dive into Properties, we need to understand the concept of Encapsulation.

Encapsulation is the process of making sure that "sensitive" data is hidden from users. To achieve this, you must:

1. Declare class fields as private.
2. Provide public get and set methods, through a Property, to access and update the value of a private field.

What are Properties?

A property is like a combination of a variable and a method. It cannot take any parameters, but it provides two special blocks of code called accessors: the get accessor and the set accessor.

• The get method returns the value of the variable.
• The set method assigns a value to the variable. (The value keyword represents the value we are assigning).

using System;

class Person 
{
  // private field (hidden from the outside)
  private string name; 
  // public property (exposed to the outside)
  public string Name 
  {
    get { return name; }   // returns the private field
    set { name = value; }  // updates the private field
  }
}
class Program 
{
  static void Main(string[] args) 
  {
    Person myObj = new Person();
    // The 'set' accessor is called here:
    myObj.Name = "Liam"; 
    // The 'get' accessor is called here:
    Console.WriteLine(myObj.Name); 
  }
}

Naming Convention: It is standard practice to use a lowercase letter for the private field (name) and an uppercase letter for the public property (Name).

Automatic Properties (Short-hand)

C# provides a brilliant shortcut! If you don't need any special logic inside your get and set accessors, you can use Automatic Properties.

With automatic properties, you do not even need to define the private field. C# will secretly create one for you behind the scenes.

using System;

class Person 
{
  // Automatic property! No private field needed.
  public string Name { get; set; } 
}
class Program 
{
  static void Main(string[] args) 
  {
    Person myObj = new Person();
    myObj.Name = "Liam";
    Console.WriteLine(myObj.Name);
  }
}

Why Use Properties?

• Better Control: You can restrict how a field is modified. For example, in the set accessor, you could add logic to ensure the age is never negative before assigning it.
• Read-Only: You can make a property read-only by omitting the set accessor.
• Flexibility: You can change internal implementation details later without breaking the code of other programmers who are using your class!