On Tuesday, 17 May 2022 at 00:10:55 UTC, Alain De Vos wrote:
Let's say a shape is ,a circle with a radius ,or a square with
a rectangular size.
I want to pass shapes to functions, eg to draw them on the
screen,
draw(myshape) or myshape.draw();
But how do i implement best shapes ?
In addition to all the answers, just remember that if you want to
make a square class then it should inherit from the shape class
and not the rectangle class.
It might seem like the obvious rule is for square to inherit
rectangle, since a square is a rectangle, but it's only true on
the surface, not in functionality.
An example is below:
```d
void changeRectangle(Rectangle rectangle, int amount)
{
rectangle.length = rectangle.length + amount;
}
...
// While this works, then it's functional wrong as you must
change both the length/height of a square, since they cannot
differ.
changeRectangle(new Square(100, 100), 50);
```
You might think that it's easy to just not call changeRectangle
with a square, but what if you store the rectangles in a list,
map, get it from an external data source etc. then it starts
being more and more complex and for no reason at all!
I know your post really isn't about such things, but I think it's
a good thing to learn already.
