JSFiddle - React, Tailwind, and code Playground

JavaScript

/*array declaration*/ 
/*var names=[,"first","second","third",,]
    

document.write(names[0] + '<br>' + names[1] +'<br>' + names[2] + '<br>' + names[3] + '<br>');



var mynames= new Array();

mynames[0] = "jack";
mynames[1] = "harris";
mynames[2] = "david";

document.write(mynames[0] + '<br>' + mynames[1]);*/


/*declaration of object literals*/
/*var Sales = "Toyota";   
  
function CarTypes(name) {   
  if (name == "Honda")   
     return name;   
  else  
     return "Sorry, we don't sell " + name + ".";   
}   
  
var car = { myCar: "Saturn", getCar: CarTypes("Honda"), special: Sales };   
var car1= { myCar:"Mercendes", getCar: CarTypes("Henda"), special: Sales};  
document.write(car.myCar);   // Saturn  
document.write('<br>');
document.write(car.getCar);  // Honda   
document.write('<br>');
document.write(car.special); // Toyota 
document.write('<br>');
document.write(car1.myCar);   
document.write('<br>');
document.write(car1.getCar);  
document.write('<br>');
document.write(car1.special); 

*/


var car2={manycars:{a:"first",b:"second"},7:"third"};

document.write(car2.manycars.b);
document.write(car2[7]);