重写基类的实现，以便从继承的基类函数进行的调用也将调用overidden函数

Question

I have to override a function in a base class in such a way that calls to inherited functions also lead to calls to this overridden function instead of the base implementation.

class base_class
{
    string abc;
    public int get_1()
    {
        return 1;
    }
    public  int get_number()
    {
        return get_1()+1;
    }
}

class der_class : base_class
{
    public int get_1()
    {
        return 2;
    }
}
class Program
{
    static void Main(string[] args)
    {
        der_class abc = new der_class();
        Console.WriteLine(abc.get_number());
        Console.ReadKey();
    }
}

This prints 2. How can I get the output to be 3 by making the get_number to call overridden get_1?

Answer 1

You need the override keyword to actually override a method, otherwise you are hiding it.

class der_class : base_class
{
    // note the word override here!
    public override int get_1()
    {
        return 2;
    }
}

Also, you need to make the method virtual in the base class:

class base_class
{
    string abc;
    // note the word virtual here!
    public virtual int get_1()
    {
        return 1;
    }
    public  int get_number()
    {
        return get_1()+1;
    }
}