JSFiddle - React, Tailwind, and code Playground

HTML

<div id="first_book">Hi</div>
<div id="second_book"></div>
<div id="third_book"></div>

JavaScript

function Person(){}
Person.prototype.favorite_books = [];

var george = new Person();
george.favorite_books = ["Curious George"];

var kate = new Person();
kate.favorite_books = ["The Da Vinci Code", "Harry Potter"];

var people = [kate, george];

$('#first_book').text(people[0].favorite_books[0]);

var people_copy = $.extend(true, [], people);
people_copy[0].favorite_books[0] = "Ender's Game";

$('#second_book').text(people[0].favorite_books[0]);

var people_each_copy = [];
$.each(people, function(i,obj) {
    people_each_copy.push($.extend(true,{},obj)); 
});

people_each_copy[0].favorite_books[0] = "Winnie the Pooh"

$('#third_book').text(people[0].favorite_books[0]);