Inheritance (Extending a Class)

In this lesson you will learn how to extend a class through inheritance in C#, so classes that share characteristics can reuse code. This is for anyone searching for "C# inheritance how to use".

You inherit with : ParentClassName. Using virtual and override lets a child class replace a method from the parent.

The sample code makes Animal the parent, has Dog inherit from it with : Animal, and replaces the parent's method with override. This is the classic technique of taking a shared "animal" blueprint and adding a dog's own way of making a sound.

A common stumbling block for beginners is forgetting the virtual/override pair. Without virtual on the parent, the child cannot override the method and you get a compile error.

In real-world development, leaning on inheritance too heavily can make the relationships between classes overly tangled, so design balance matters.

📖 Reference code

class Animal {
    public string Name;
    public Animal(string name) { Name = name; }
    public virtual string Speak() { return Name + " makes a sound"; }
}

class Dog : Animal {
    public Dog(string name) : base(name) {}
    public override string Speak() { return Name + " says \"Woof\""; }
}

Dog dog = new Dog("Rex");
Console.WriteLine(dog.Speak());

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🧪 This site can't compile or run C# directly, so it checks on the spot whether what you typed matches the reference code (scoring happens entirely in your browser — nothing is sent anywhere).