JSFiddle - React, Tailwind, and code Playground

JavaScript

(function () {
   "use strict"; 
    let obj = {};
    let arr = [];
    let str = "";
    
    
    console.log("Array iterator:  " + arr[Symbol.iterator]);
    console.log("String iterator:  " + str[Symbol.iterator]);
    console.log("Object iterator:  " + obj[Symbol.iterator]);
    
    for (var i of arr) {
        console.log(i);
    }
    for (var i of str) {
        console.log(i);
    }
    //for (var i of obj) {  //runtime error here:  'undefined is not a function'
    //    console.log(i);  
    //}
})();