JSFiddle - React, Tailwind, and code Playground

JavaScript

var bob = {
    firstName: "Bob",
    lastName: "Jones",
    phoneNumber: "(650) 777-7777",
    email: "[email protected]"
};

var mary = {
    firstName: "Mary",
    lastName: "Johnson",
    phoneNumber: "(650) 888-8888",
    email: "[email protected]"
};

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

function add (firstName, lastName, email, telephone) {
var person = {
	firstName: firstName,
	lastName: lastName,
	email: email,
	telephone: telephone};

	contacts[contacts.length] = person;

};
add("John","Doe", "[email protected]", "693-579-430");
list();