// helper function to check equality
static void DisplayWhetherEqual(FoodBaseRefType food1, FoodBaseRefType food2)
{
if (food1 == food2)
{
Console.WriteLine(string.Format($"{food1} == {food2}"));
}
else
{
Console.WriteLine(string.Format($"{food1} != {food2}"));
}
}
public override bool Equals(object obj)
{
if (obj == null)
{
return(false);
}
if (ReferenceEquals(obj, this))
{
return(true);
}
if (obj.GetType() != this.GetType())
{
return(false);
}
FoodBaseRefType rhs = obj as FoodBaseRefType;
return(this._name == rhs._name && this._group == rhs._group);
}
public static void RunDemo()
{
Console.WriteLine("RefTypeEquality demo: Demonstrates two reference types- \n" +
"FoodBase(base type) and CookedFood (sealed derived type)\n" +
"for which equality has been implemented correctly\n");
FoodBaseRefType apple = new FoodBaseRefType("apple", FoodGroup.Fruit);
CookedFood stewedApple = new CookedFood("stewed", "apple", FoodGroup.Fruit);
CookedFood bakedApple = new CookedFood("baked", "apple", FoodGroup.Fruit);
CookedFood stewedApple2 = new CookedFood("stewed", "apple", FoodGroup.Fruit);
FoodBaseRefType apple2 = new FoodBaseRefType("apple", FoodGroup.Fruit);
DisplayWhetherEqual(apple, stewedApple);
DisplayWhetherEqual(stewedApple, bakedApple);
DisplayWhetherEqual(stewedApple, stewedApple2);
DisplayWhetherEqual(apple, apple2);
DisplayWhetherEqual(apple, apple);
Console.WriteLine();
}