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C# C# Objects Inheritance Inheritance

Posted by Alexander Gallardo
Alexander Gallardo
617 Points

Can someone help me with this damn inheritance problem??

I literally looked up how to do it and its still wrong is this a glitch?!?!?!

Polygon.cs 
namespace Treehouse.CodeChallenges
{
    class Polygon : Square 
    {
        public readonly int NumSides;

        public Polygon(int numSides)
        {
            NumSides = numSides;
        }
    }
}

class Square: Polygon 
{
    public readonly int SideLength;

    public Square (int sideLength): base (4)
    {

    SideLength = sideLength; 

    }
}

1 Answer

andren
andren
28,558 Points
andren
andren
28,558 Points

There are two issues with your code:

  1. The Polygon class should not inherit from Square class.

  2. The Square class should be inside the same namespace as the Polygon class.

Like this:

namespace Treehouse.CodeChallenges
{
    class Polygon
    {
        public readonly int NumSides;

        public Polygon(int numSides)
        {
            NumSides = numSides;
        }
    }
    class Square: Polygon 
    {
        public readonly int SideLength;

        public Square (int sideLength): base (4)
        {
            SideLength = sideLength; 
        }
    }
}
Connor Whyte
Connor Whyte
1,395 Points

Would someone be able to explain this to me? The base(4) specifically. I spent a while putting in a variety of variables like in the tutorial with x and y. I put in NumSides and numSides instead.

andren
andren
28,558 Points
andren
andren
28,558 Points

The base call is essentially you calling the constructor of the parent class. To put it a bit more simply, what would you write in order to create an instance of Polygon with 4 sides? You would type new Polygon(4). The base call is essentially doing exactly that, it is calling the Polygon constructor and passing in whatever value you provided in the base call.

So the value you type in the base call is send directly to the parent's constructor method. That means that if the parent class' constructor had two parameter you would need to provide two arguments to the base call and so on.

In the previous lecture the parent class' constructor required an x and y argument, since those were also required by the constructor of the child class it was possible to just pass those parameters along, as passing in variables in the super call is valid. But that is not possible for the challenge code since the child constructor does not require you to pass in the number of sides, which is what the Polygon constructor needs to be passed.

Edit: Added a bit more info relating to the previous video lecture.