Invocation

To invoke an instance method you first need an instance of the class.

You then write . followed by the name of the instance method and a list of arguments.¹

class Elmo {
    void talkAboutRocko() {
        System.out.println("ROCKO'S NOT ALIVE!!")
    }
}

void main() {
    Elmo elmo = new Elmo();
    elmo.talkAboutRocko();
}