public override bool Equals(object obj)
{
if (!base.Equals(obj))
{
return(false);// check inherited fields first
}
CookedFood rhs = (CookedFood)obj;
return(this._cookingMethod == rhs._cookingMethod);//check added fields
}
static void Main()
{
//ReferenceEquality();
//StringEquality();
//DefaultStaticObjectBoolEqualsOfDotNet();
//ValueTypeEquality();
var apple = new Food("apple", FoodGroup.Fruit);
var stewedApple = new CookedFood("stewed", "apple", FoodGroup.Fruit);
var bakedApple = new CookedFood("baked", "apple", FoodGroup.Fruit);
var stewedApple2 = new CookedFood("stewed", "apple", FoodGroup.Fruit);
var apple2 = new Food("apple", FoodGroup.Fruit);
DisplayWhetherEqualUsingEqualityOperator(apple, stewedApple);
DisplayWhetherEqualUsingEqualityOperator(stewedApple, bakedApple);
DisplayWhetherEqualUsingEqualityOperator(stewedApple, stewedApple2);
DisplayWhetherEqualUsingEqualityOperator(apple, apple2);
DisplayWhetherEqualUsingEqualityOperator(apple, apple);
Console.WriteLine("Using class's equals method");
DisplayWhetherEqualUsingFoodsEquality(apple, stewedApple);
DisplayWhetherEqualUsingFoodsEquality(stewedApple, bakedApple);
DisplayWhetherEqualUsingFoodsEquality(stewedApple, stewedApple2);
DisplayWhetherEqualUsingFoodsEquality(apple, apple2);
DisplayWhetherEqualUsingFoodsEquality(apple, apple);
Console.WriteLine("Using static Object.Equals");
DisplayWhetherEqualUsingStaticObjectEquality(apple, stewedApple);
DisplayWhetherEqualUsingStaticObjectEquality(stewedApple, bakedApple);
DisplayWhetherEqualUsingStaticObjectEquality(stewedApple, stewedApple2);
DisplayWhetherEqualUsingStaticObjectEquality(apple, apple2);
DisplayWhetherEqualUsingStaticObjectEquality(apple, apple);
}
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();
}