JSFiddle - React, Tailwind, and code Playground
JavaScript
const names = ['Batman', , 'Bane'];
// No hole
console.log(0 in names); // logs true
// Hole
console.log(1 in names); // logs false
const names = ['Batman', , 'Bane'];
// No hole
console.log(0 in names); // logs true
// Hole
console.log(1 in names); // logs false