Field Access
Within an instance method's definition, you can access the values of any fields declared in the class by just writing their name.
class Elmo {
    int age;
    void sayHello() {
        IO.println("Hi, I'm Elmo");
        IO.print("I am ");
        // You can use elmo's age by just writing "age"
        IO.print(age);
        IO.println(" years old.");
    }
}
void main() {
    Elmo elmo = new Elmo();
    elmo.age = 3;
    elmo.sayHello();
}