Question

What are the different ways to create sparse arrays?

Answer 1

There are 4 different ways to create sparse arrays in JavaScript

1. Array literal: Omit a value when using the array literal

   const justiceLeague = ["Superman", "Aquaman", , "Batman"];
   console.log(justiceLeague); // ['Superman', 'Aquaman', empty ,'Batman']
2. Array() constructor: Invoking Array(length) or new Array(length)

   const array = Array(3);
   console.log(array); // [empty, empty ,empty]
3. Delete operator: Using delete array[index] operator on the array

   const justiceLeague = ["Superman", "Aquaman", "Batman"];
   delete justiceLeague[1];
   console.log(justiceLeague); // ['Superman', empty, ,'Batman']
4. 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]