gistfile1.js

// Our person constructor
function Person (name, age) {
    this.name = name;
    this.age = age;
}

// We can make a function which takes persons as arguments
// This one computes the difference in ages between two people
var ageDifference = function(person1, person2) {
    return person1.age - person2.age;
};

// Make a new function, olderAge, to return the age of
// the older of two people


// Let's bring back alice and billy to test our new function
var alice = new Person("Alice", 30);
var billy = new Person("Billy", 25);

console.log("The older person is "+olderAge(alice, billy));