address_book.js

var bob = {
    firstName: "Bob",
    lastName: "Jones",
    phoneNumber: "(650) 777-7777",
    email: "bob.jones@example.com"
};

var mary = {
    firstName: "Mary",
    lastName: "Johnson",
    phoneNumber: "(650) 888-8888",
    email: "mary.johnson@example.com"
};

var contacts = [bob, mary];

function printPerson(person) {
    console.log(person.firstName + " " + person.lastName);
}

function list() {
	var contactsLength = contacts.length;
	for (var i = 0; i < contactsLength; i++) {
		printPerson(contacts[i]);
	}
}

/*Create a search function
then call it passing "Jones"*/
var search = function(lastName){
    var contactsLength = contacts.length;
    for(var i=0; i<contactsLength; i++){
        if(contacts[i].lastName == lastName){
            printPerson(contacts[i]);   
        }
    }
}
search("Jones");

var add = function(firstName, lastName, email, phoneNumber){
    var contact = {
        firstName: firstName,
        lastName: lastName,
        email: email,
        phoneNumber: phoneNumber
    };
    contacts[contacts.length] = contact;
}

add("Tony", "Stark", "antony@example.com", "(999) 888 - 777");
list();