Пример #1
0
        private static void ValueTypeEquality()
        {
            var banana         = new FoodItem("Banana", FoodGroup.Fruit);
            var bananaTwo      = new FoodItem("Banana", FoodGroup.Fruit);
            var chocolate      = new FoodItem("Chocolate", FoodGroup.Vegetables);
            var bananaSmoothie = new FoodItem("Chocolate Smoothie", FoodGroup.Fruit);

            var areEqual = object.Equals(banana, chocolate);

            Console.WriteLine(areEqual);
            Console.WriteLine(banana == bananaSmoothie);

            var dictionaryOfFoodGroups = new Dictionary <FoodItem, string>();

            Console.WriteLine(banana.GetHashCode());
            dictionaryOfFoodGroups.Add(banana, banana.Name);
            //This line should throw an exception as both banana and bananaTwo should have same hash code
            Console.WriteLine(bananaTwo.GetHashCode());
            dictionaryOfFoodGroups.Add(bananaTwo, bananaTwo.Name);
        }
Пример #2
0
        static void Main(string[] args)
        {
            string apple0 = "Apple";
            string apple1 = "App" + "le";

            Console.WriteLine("strings are {0} and {1}", apple0, apple1);

            Console.WriteLine(apple0 == apple1);
            Console.WriteLine(ReferenceEquals(apple0, apple1)); // return True because compiler will optimize memory and two var will refer to one string;

            string str1 = "erkl\u00e4ren";                      //combining characters a + "
            string str2 = "erkla\u0308ren";

            StringComparisons.DisplayAllComparisons(str1, str2);

            str1 = "Stra\u00dfe"; //expansion character, not depend on culture
            str2 = "Strasse";
            StringComparisons.DisplayAllComparisons(str1, str2);

            Console.WriteLine("Current culture is " + Thread.CurrentThread.CurrentCulture);

            str1 = "apple";
            str2 = "PINEAPPLE";
            StringComparisons.DisplayAllComparisons(str1, str2);

            int result = string.Compare("lemon", "LEMON", StringComparison.OrdinalIgnoreCase);

            Console.WriteLine("Compare result is " + result);

            result = string.Compare("lemon", "LEMON", StringComparison.Ordinal);
            Console.WriteLine("Compare result is " + result);

            result = string.Compare("lemon", "lime", StringComparison.Ordinal);
            Console.WriteLine("Compare result is " + result);

            Console.WriteLine("********************************************");

            CalorieCount cal300 = new CalorieCount(300);
            CalorieCount cal400 = new CalorieCount(400);

            DisplayOrder(cal300, cal400);
            DisplayOrder(cal400, cal300);
            DisplayOrder(cal300, cal300);

            if (cal300 < cal400)
            {
                Console.WriteLine("cal300 < cal400");
            }

            if (cal300 == cal400)
            {
                Console.WriteLine("cal300 = cal400");
            }

            Console.WriteLine("********************************************");

            Food       apple        = new Food("apple", FoodGroup.Fruit);
            Food       apple2       = new Food("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);

            Console.WriteLine(apple);
            Console.WriteLine(stewedApple);

            DisplayWhetherEqual(apple, stewedApple);
            DisplayWhetherEqual(stewedApple, bakedApple);
            DisplayWhetherEqual(stewedApple, stewedApple2);
            DisplayWhetherEqual(apple, apple2);
            DisplayWhetherEqual(apple, apple);

            Console.WriteLine("********************************************");

            FoodItem bananai1   = new FoodItem("banana", FoodGroup.Fruit);
            FoodItem bananai2   = new FoodItem("banana", FoodGroup.Fruit);
            FoodItem chocolatei = new FoodItem("chocolate", FoodGroup.Sweets);

            Console.WriteLine("banana1 == banana2: " + (bananai1 == bananai2));
            Console.WriteLine("banana2 == chocolate: " + (bananai2 == chocolatei));
            Console.WriteLine("banana1 == chocolate: " + (bananai1 == chocolatei));

            Console.WriteLine("********************************************");

            str1 = "Click me";
            str2 = string.Copy(str1);
            DiaplayWhwtherArgsEqual(str1, str2);

            Console.WriteLine("********************************************");

            Tuple <int, int> tuple1 = Tuple.Create(1, 3);
            Tuple <int, int> tuple2 = Tuple.Create(1, 3);

            Console.WriteLine("Reference " + ReferenceEquals(tuple1, tuple2));
            Console.WriteLine("operator " + (tuple1 == tuple2));// not overloaded for tuples = will compare references
            Console.WriteLine("method " + tuple1.Equals(tuple2));

            Console.WriteLine("********************************************");

            str1 = "Click me";
            str2 = string.Copy(str1);

            Console.WriteLine("Reference " + ReferenceEquals(str1, str2));
            Console.WriteLine("operator " + AreStringEqualOp(str1, str2));
            Console.WriteLine("method " + AreStringEqualsMethod(str1, str2));

            Console.WriteLine("********************************************");

            Button button1 = new Button();

            button1.Text = "Click me";
            Button button2 = new Button();

            button2.Text = "Click me";

            Console.WriteLine("operator " + AreButtonEqualOp(button1, button2));
            Console.WriteLine("method " + AreButtonEqualsMethod(button1, button2));


            Console.WriteLine("********************************************");

            Console.WriteLine("operator " + AreIntsEqualOp(3, 3));
            Console.WriteLine("method " + AreIntsEqualsMethod(3, 3));

            Console.WriteLine("********************************************");

            Food banana  = new Food("banana");
            Food banana2 = new Food("banana");

            Food chocolate = new Food("chocolate");

            Console.WriteLine(banana.Equals(chocolate));
            Console.WriteLine(banana.Equals(banana2));                  // virtual object.Equals()
            Console.WriteLine(object.Equals(banana, banana2));          // static object.Equals() - if one of the objects is null
            Console.WriteLine(object.ReferenceEquals(banana, banana2)); // ALWAYS check reference to same instance

            Console.WriteLine("********************************************");

            FoodStruct bananas  = new FoodStruct("banana");
            FoodStruct bananas2 = new FoodStruct("banana");

            Console.WriteLine(bananas.Equals(bananas2));
            //Console.WriteLine(bananas == bananas2);// operator == should be overloaded

            Console.ReadLine();
        }