JSFiddle - React, Tailwind, and code Playground

by pjnovas

JavaScript

//Abrir consola con F12
// Mas info en: http://www.fernetjs.com/2011/10/abajo-el-alert-arriba-el-console-log/

// Para limpiar la consola, ingresar clear(); en la misma.

// Parte 1 ************************************************************
var arr = [];
arr[1] = 'chau';
arr[2] = 'hola';

for (var ele in arr) {
    //1era iteración: ele === 1
    //2da iteración: ele === 2
    console.log(ele);
}

// Parte 2 ************************************************************
var persona = {
    nombre : 'Pepe',
    edad: 25
};
 
if (persona.nombre === persona['nombre'])
   console.log('loco, no?');

for (var p in persona){
    //1er iteración: p === 'nombre'
    //2da iteración: p === 'edad'
    console.log(p);
}

// Parte 3 ************************************************************
Array.prototype.unMetodoNuevo = function(){ alert('nuevo metodo');};
var arr = [];
 
for (var ele in arr){
    //Ingresará una vez y ele será la function unMetodoNuevo
    console.log(ele);
}

// Parte 4 ************************************************************
var arr2 = [];
arr2[1] = 'hola';
arr2[2] = 'chau';

for (var i=0; i < arr2.length; i++){
    //i === 0: arr[0] === undefined;
    //i === 1: arr[1] === 'hola';
    //i === 2: arr[2] === 'chau';
    console.log(arr2[i]);
}