Q435: What are the different ways to create sparse arrays? - JavaScript Internals (521 Qs)

There are 4 different ways to create sparse arrays in JavaScript

Array literal: Omit a value when using the array literal

    const justiceLeague = ["Superman", "Aquaman", , "Batman"];
    console.log(justiceLeague); // ['Superman', 'Aquaman', empty ,'Batman']

Array() constructor: Invoking Array(length) or new Array(length)

    const array = Array(3);
    console.log(array); // [empty, empty ,empty]

Delete operator: Using delete array[index] operator on the array

    const justiceLeague = ["Superman", "Aquaman", "Batman"];
    delete justiceLeague[1];
    console.log(justiceLeague); // ['Superman', empty, ,'Batman']

Increase length property: Increasing length property of an array

    const justiceLeague = ["Superman", "Aquaman", "Batman"];
    justiceLeague.length = 5;
    console.log(justiceLeague); // ['Superman', 'Aquaman', 'Batman', empty, empty]