When you pass a reference type by value to a method, you pass in a reference to the object. The method can change the object, but can’t change the reference.
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| public static void AnnotateMotto(Dog d){ // Change the dog's motto d.Motto = d.Motto + " while panting";} |
You can also pass a reference type by reference, which means that the method can change not only the contents of the object pointed to, but change the reference, causing it to refer to a different object.
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| public static void FindNewFavorite(ref Dog fav){ fav.Motto = "No longer the favorite"; foreach (Dog d in AllDogs) { if (d.Motto.Contains("ball")) fav = d; }} |
Below is an example of calling this method.
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| Dog kirby = new Dog("Kirby");kirby.Motto = "Retrieve balls";Dog jack = new Dog("Jack");jack.Motto = "Growl at people";Dog myFav = jack;Dog.FindNewFavorite(ref myFav);Console.WriteLine(myFav.Name); // Kirby |