Understanding C# Method Overriding and Method Hiding

Understanding C# Method Overriding and Method Hiding

Introduction

In C#, you can use inheritance to create new classes based on existing ones. When a method is defined in both the base class and the derived class, there are two ways to handle the method implementation: method overriding and method hiding.

Method Overriding

Method overriding is a feature of inheritance that allows a derived class to provide its own implementation of a method that is already defined in the base class. To override a method, you use the override keyword in the derived class.

class ClassA
{
    public virtual void T()
    {
        // Base implementation
    }
}

class ClassB : ClassA
{
    public override void T()
    {
        // Derived implementation
    }
}

In the example above, ClassB extends ClassA and overrides the T method. When you create an instance of ClassB, calling T will execute the implementation in ClassB. However, if you cast the instance as ClassA, the base implementation will be executed instead.

ClassA a = new ClassB();
a.T(); // Calls the implementation in ClassB

Method Hiding

Method hiding, on the other hand, is a concept in C# that allows a derived class to provide its own implementation of a method with the same name as a method in the base class. This hides the base class method from the derived class, and calling the method on a derived class instance will execute the derived implementation.

To hide a method, you use the new keyword in the derived class.

class ClassA
{
    public void T2()
    {
        // Base implementation
    }
}

class ClassB : ClassA
{
    public new void T2()
    {
        // Derived implementation
    }
}

In the example above, ClassB hides the T2 method from ClassA. Calling T2 on an instance of ClassB will execute the implementation in ClassB, regardless of whether the instance is cast as ClassA or ClassB.

ClassA a = new ClassB();
a.T2(); // Calls the implementation in ClassA

Conclusion

Understanding the difference between method overriding and method hiding is crucial for writing effective object-oriented code in C#. By using method overriding, you can provide specialized implementations in derived classes while still benefiting from polymorphism. Method hiding, on the other hand, allows you to completely replace the implementation of a method in the derived class. Make sure to choose the right approach based on your specific requirements and design goals.

I hope this article clarifies the concepts of method overriding and method hiding in C#. If you have any further questions, please feel free to ask in the comments section below.

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