访问基类重写的ToString方法中的子类对象

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

    public override string ToString()
    {
        return $"Name: {Name}, Age: {Age}";
    }
}

public class Student : Person
{
    public string School { get; set; }
    public int Grade { get; set; }

    public override string ToString()
    {
        return $"Name: {Name}, Age: {Age}, School: {School}, Grade: {Grade}";
    }
}

public class Program
{
    public static void Main(string[] args)
    {
        Person person = new Person { Name = "John", Age = 25 };
        Student student = new Student { Name = "Alice", Age = 18, School = "ABC School", Grade = 12 };

        Console.WriteLine(person.ToString());   // Output: Name: John, Age: 25
        Console.WriteLine(student.ToString());  // Output: Name: Alice, Age: 18, School: ABC School, Grade: 12
    }
}