static void Main(string[] args)
{
Fruit fruit = new Fruit("Tomato", 10, KnownColor.Red, true);
// Uncomment this line and see that C# doesn't allow the default construct as we already have definited at least one constructor.
//fruit = new Fruit();
Pear pear1 = new Pear();
// This is the oposite of the first example. You cannot call a constructor this undefinited or definited only on the parent.
//pear1 = new Pear("Pear", 10, KnownColor.Green, true);
AsianPear asianPear = new AsianPear();
Console.WriteLine(asianPear.ToString());
Console.WriteLine(asianPear.Origin);
Console.WriteLine();
// Here I am convecting back the asianPear into it parent class
Pear pear2 = (Pear)asianPear;
// See here that the method toString still keep the new implementation specific to AsianPear
Console.WriteLine(pear2.ToString());
//Now the following line is now throwing an error as the property hasn't been defined either on Fruit Class or the Pear Class
//Console.WriteLine(pear2.Origin);
//Here the normal Pear object is using the behavior defined in the Fruit object instead.
Console.WriteLine(pear1.ToString());
Console.WriteLine();
//This is an example of using interface.
IPlant plant = new Pyrus();
plant.Harvest();
plant.Harvest(DateTime.Today);
plant.Harvest(DateTime.Today.AddDays(10));
plant.Harvest(DateTime.Today.AddDays(-10));
// Here I am trying to access a function undefined by the Interface. Visual studio won't let me compile this line.
//Console.WriteLine(plant.GetLocation());
// But this line does work as we are casting first into the proper object.
Console.WriteLine(((Pyrus)plant).GetLocation());
Console.WriteLine();
// Now see the difference with the appletree interface.
var appleTree = new AppleTree();
// Here is checkin if the appletree does implement the interface IPlant
if (appleTree is IPlant)
{
// This casting into IPlant.
plant = (IPlant)appleTree;
plant.Harvest();
plant.Harvest(DateTime.Today);
plant.Harvest(DateTime.Today.AddDays(10));
plant.Harvest(DateTime.Today.AddDays(-10));
Console.WriteLine();
}
//Here plant should be an appleTree. But we don't know the base type.
//So we are trying to cast it into a Pyrus
Pyrus applePear = plant as Pyrus;
// If the conversion failed, there won't be an error but the value will be null
if (applePear != null)
{
// See are it isn't been run.
applePear.Harvest();
applePear.Harvest(DateTime.Today);
applePear.Harvest(DateTime.Today.AddDays(10));
applePear.Harvest(DateTime.Today.AddDays(-10));
}
//But this casting will fail at runtime
applePear = (Pyrus)plant;
}
