w3docs logo
  1. Snippets
  2. JavaScript
  3. How to Create a Two Dimensional Array in JavaScript

How to Create a Two Dimensional Array in JavaScript

The two-dimensional array is a set of items sharing the same name. The two-dimensional array is an array of arrays, that is to say, to create an array of one-dimensional array objects. They are arranged as a matrix in the form of rows and columns.

JavaScript suggests some methods of creating two-dimensional arrays.

Array Constructor

You can use the array constructor and the for loop to create a 2D array like this:

w3docs logo Javascript array constructor
const m = 4; const n = 5; let arr = new Array(m); // create an empty array of length n for (var i = 0; i < m; i++) { arr[i] = new Array(n); // make each element an array } console.log(arr); // Output: [ [ <5 empty items> ], [ <5 empty items> ], [ <5 empty items> ], [ <5 empty items> ] ]

Array Literal Notation

Lieteral notation method can also be used to create 2D arrays:

w3docs logo Javascript array literal notation
const m = 4; const n = 5; // Note 2nd dimention is not relevant here let arr = []; for (var i = 0; i < m; i++) { arr[i] = []; } console.log(arr); // Output: [ [], [], [], [] ]

The Array.from() method

The Array.from() method will return an array object from any JavaScript object with the length property or an iterable object.

w3docs logo Javascript array literal notation
const m = 4; const n = 5; let arr = Array.from(Array(m), () => new Array(n)); console.log(arr); // Output: [ [ <5 empty items> ], [ <5 empty items> ], [ <5 empty items> ], [ <5 empty items> ] ]

The Array.prototype.map()Method

You can also call the map() function directly:

w3docs logo How to Create a Two Dimensional Array in JavaScript
const m = 4; const n = 5; let arr = Array(m).fill().map(() => Array(n)); console.log(arr); // Output: [ [ <5 empty items> ], [ <5 empty items> ], [ <5 empty items> ], , [ <5 empty items> ] ]

Multidimensional Arrays

Multidimensional arrays are known in JavaScript as arrays inside another array as they are created by using another one-dimensional array.

They can have more than two dimensions. A two-dimensional array is also called a matrix or a table of rows and columns.

Do you find this helpful?