Quick question about instance variables

[Jake Miller]

Here is a class:

class Dog {
int size;
String name;

void bark() {
if(size > 60) {
System.out.println("Woof! Woof!");
} else if(size > 14) {
System.out.println("Ruff! Ruff!");
} else {
System.out.println("Yip! Yip!");
}
}
}

And an object:

class DogTestDrive {
public static void main(String[] args) {
Dog one = new Dog();
one.size = 70;
Dog two = new Dog();
two.size = 8;
Dog three = new Dog();
three.size = 35;

one.bark();
two.bark();
three.bark();
}
}

So what exactly are the instance variables in this situation? Size and name? Name is not used again, so I am not even entirely sure why it is used.

[James Hambrick]

not sure why name it there either if it is not used, yes size and name are instance variables because you can call them using one.size, two.size. If size or name was static then they would not be instance variables but merely variables. If I am wrong someone correct me please.

[Jon Anslow]

Originally posted by James Hambrick:
if size or name was static then they would not be instance variables but merely variables.

Just to confirm, if size and name were static then they would be known as Class variables and would be accessed via the class name. A reference of the Dog Class would not need to be created to use them.

eg:

Dog.size and Dog.name

[Bob Ruth]

In class Dog, size and name are instance variables.

In class DogTestDrive, one, two, and three are local variables on the stack.

I've seen this example before and I think it is part of a series of "snippets" and that later a constructor is used to pass in the name when a dog is instantiated.