JSFiddle - React, Tailwind, and code Playground

HTML

<p>alert(phil)</p>

JavaScript

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"*/

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


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

add("Phil", "Ace", "phil@gmail.com", "(123) 456-7890");

list();

try {
    alert(phil);
} catch (err) {
    alert(err);
}