Properties

Learn C# properties, auto-implemented properties, and get/set accessors.

What is a Property?

A property looks like a public field from the outside but is backed by get/set methods (accessors) internally. This lets you add validation or logic later without breaking any code that uses the property.

Auto-Implemented Properties

When you don't need custom logic, C# lets you skip writing a backing field manually.

class Person
{
    public string Name { get; set; }
    public int Age { get; set; }
}

var person = new Person { Name = "Meera", Age = 30 };
Console.WriteLine($"{person.Name}, {person.Age}");

Custom get/set Logic

class Product
{
    private decimal price;

    public decimal Price
    {
        get => price;
        set
        {
            if (value < 0) throw new ArgumentException("Price can't be negative.");
            price = value;
        }
    }
}

var product = new Product();
product.Price = 49.99m; // runs through the validation in set
Console.WriteLine(product.Price);

Output

Click Run to see what this code prints.

Read-Only Properties

A property with only a `get` accessor (or `init` since C# 9, settable only during object initialization) can't be changed after the object is created.

class Order
{
    public string Id { get; }

    public Order(string id)
    {
        Id = id; // allowed only in the constructor
    }
}

FAQs

Should I ever use plain public fields instead of properties?

Generally, prefer properties for anything public — they give you room to add validation later without a breaking change to your class's public API.

Summary

Properties expose controlled access to a class's data.
Auto-implemented properties skip writing a backing field manually.
Custom get/set logic lets you validate values on assignment.

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