JSFiddle - React, Tailwind, and code Playground

JavaScript

function World() {
    this.mankind = new Mankind(this);
    this.getName = function(id) {
        console.log('getName', this);
        return this.mankind.people[id].name;
    }
    alert(this.getName(0));
    this.tmpString = '';
    for(var i = 0; i < this.mankind.city.length; i++)
    {
        this.tmpString += this.getName(i) + ' ';
    }
    alert('Здесь проживают: ' + this.tmpString);
}

function Mankind(world) {
    this.people = new Array();
    this.people[0] = new Man(this, 'Vasily');
    this.people[1] = new Man(this, 'Alessandra');
    this.city = [0, 1];
}

function Man(mankind, name) {
    this.name = name;
}

new World();