Assuming that we have the class animal,
we can define some variables
that can be used to store animals.
Remember that the class is also a data type.
We can also create some animals
to put in those variables.
To create an animal,
we use the syntax *classname*(),
i e the name of the class
followed by a pair of parentheses.
animal some_animal;
some_animal = animal();
animal my_dog = animal();To access a member variable in an object,
we use the syntax *object-expression*->*variable-name*,
i e the object followed by the operator ->
followed by the name of the variable.
my_dog->name = "Fido";
my_dog->weight = 10.0;
some_animal->name = "Glorbie";
write("My dog is called " + my_dog->name + ".\n");
write("Its weight is " + my_dog->weight + ".\n");
write("That animal is called " + some_animal->name + ".\n");Most objects need some initial values for its member variables. For example, every animal needs a name and a weight. One way to handle this is to set those variables separately, as we have done above. A better way is to design the class in a way that lets it set the variables immediately when an object is cloned from the class. You can then give the values when cloning:
animal piglet = animal("Piglet", 6.3);We can call a method in an object,
with a similar "->" syntax:
my_dog->eat("quiche"); // Real dogs eat quiche.
write("Its weight is now " + my_dog->weight + ".\n");