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C# C# Objects Inheritance Inheritance

Posted by babasariffodeen
babasariffodeen
6,475 Points

I do not understand the : base part. What is it doing?

I really do not understand what happens when you've created the Square base class (derived from Polygon) and then thereafter you state parameter but followed by : and the word 'base'.

Please can someone explain this to me using examples other than squares/polygons?

Thank you

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

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

1 Answer

Steven Parker
Steven Parker
230,995 Points
Steven Parker
Steven Parker
230,995 Points

:point_right: base refers to the parent class that the current one inherits from.

A derived class constructor always calls its parent class constructor first. Typically, there is no special syntax and the parent's default constructor is used.

In cases where the parent has no default constructor, or where an alternative constructor is desired, the ": base()" syntax can be used to specify the argument(s) to be passed to the alternative parent constructor.

babasariffodeen
babasariffodeen
6,475 Points

Thanks :)

Would it be possible to perhaps give an example of a child class calling a base class constructor? But something other than Square/Polygon. It would be helpful for me to see it used in another way. Something simple.

Thank you