var person = {
    firstName   :"Penelope",
    lastName    :"Barrymore",
    showFullName:function () {
    // "this" on the line below refers to the person object, because the showFullName function will be invoked by person object.
    console.log (this.firstName + " " + this.lastName);
    }
    }

    showFullName (); // Peter Ally
    person.showFullName() // Penelope Barrymore