3_LSP_code_problem.md

see the example classes below

class Bird {
  void Fly() { return "fly"; }
}
class Dove : Bird {
  void Fly() { return "flap"; }
}    
class Eagle : Bird {
  void Fly() { return "soar"; }
}
class Ostrich : Bird {
  void Fly() { throw exception("can't fly!"); }
}

Now what happens when you run the following:

this.birds = new List<Bird>();

this.birds.Add(new Eagle());
this.birds.Add(new Dove());
this.birds.Add(new Ostrich());

foreach(var bird in this.birds) {
  bird.Fly();
}

What happens when the Ostrich tries to fly? Or, if we substitute our Bird class for the subclass of Ostrich, will it work?

this.birds = new List<Ostrich>();
this.birds.Add(new Ostrich());
this.birds.Add(new Ostrich());

foreach(var ostrich in this.birds) {
  bird.Fly(); //can't fly
}

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