Inheritance

What is Inheritance?

Inheritance lets a class (the derived class) reuse fields and methods from another class (the base class), modeling an "is-a" relationship — a Dog is an Animal, a Car is a Vehicle.

Base and Derived Classes

class Animal
{
    public string Name;

    public void Eat()
    {
        Console.WriteLine($"{Name} is eating.");
    }
}

class Dog : Animal // Dog inherits from Animal
{
    public void Bark()
    {
        Console.WriteLine($"{Name} says woof!");
    }
}

var dog = new Dog { Name = "Rex" };
dog.Eat();  // inherited from Animal
dog.Bark(); // defined in Dog

The base Keyword

`base` lets a derived class call its parent class's constructor or methods explicitly.

class Animal
{
    public string Name;
    public Animal(string name) { Name = name; }
}

class Dog : Animal
{
    public Dog(string name) : base(name) // calls Animal's constructor
    {
    }
}

Single Inheritance

C# only allows a class to inherit from one base class directly (unlike some languages that allow multiple inheritance). To share behavior across unrelated classes, C# uses interfaces instead — covered later in this course.

FAQs

Summary