this

Within an instance method, you have access to a magic variable called this.

this is a variable that contains the current instance of the class.

You can use this to access fields or invoke any method.

class Elmo {
    int age;

    void sayHello() {
        IO.println("Hi, I'm Elmo");
        IO.print("I am ");
        IO.print(this.age);
        IO.println(" years old.");
    }

    void startTheShow(String showName) {
        this.sayHello();
        IO.println("Welcome to " + showName);
    }
}

void main() {
    Elmo elmo = new Elmo();
    elmo.age = 3;

    elmo.startTheShow("Sesame Street");
}