JavaScript Array.of method

last modified April 4, 2025

In this article we show how to create arrays using the Array.of method in JavaScript.

Array.of method

The Array.of method creates a new array instance from a variable number of arguments. Unlike the Array constructor, it treats single numeric arguments as array elements rather than setting the array length.

This method was introduced in ES6 to address inconsistencies with the Array constructor. The Array.of() method always creates an array containing its arguments as elements, regardless of the number or type of arguments.

The primary use case for Array.of() is when you need to create arrays with specific elements. It provides a consistent way to create arrays that works the same regardless of the number or type of arguments passed.

Basic Array.of example

The following example demonstrates the basic usage of the Array.of method.

const nums = Array.of(1, 2, 3, 4, 5);
console.log(nums);

We create an array containing five numeric elements. The Array.of() method takes each argument and adds it as an element to the new array. This works consistently regardless of argument types.

$ node main.js
[ 1, 2, 3, 4, 5 ]

Array.of vs Array constructor

The key difference between Array.of() and the Array constructor is shown here.

const arr1 = Array.of(7);
const arr2 = Array(7);

console.log(arr1);
console.log(arr2);

When using Array.of(7), we get an array with one element (7). With Array(7), we get an empty array with length 7. This demonstrates Array.of's consistent behavior compared to the Array constructor.

$ node main.js
[ 7 ]
[ , , , , , ,  ]

Creating arrays with mixed types

Array.of can create arrays containing elements of different types.

const mixed = Array.of(1, 'two', true, {name: 'John'}, [5, 6]);
console.log(mixed);

We create an array containing a number, string, boolean, object, and another array. Array.of() handles all these types consistently, adding each argument as an element in the new array.

$ node main.js
[ 1, 'two', true, { name: 'John' }, [ 5, 6 ] ]

Creating empty and single-element arrays

Array.of() provides consistent behavior when creating empty or single-element arrays.

const empty = Array.of();
const single = Array.of('hello');
const singleNum = Array.of(10);

console.log(empty);
console.log(single);
console.log(singleNum);

Array.of() without arguments creates an empty array. With one argument, it creates a single-element array, whether the argument is a string or number. This consistency is the main advantage over the Array constructor.

$ node main.js
[]
[ 'hello' ]
[ 10 ]

Using Array.of with array-like objects

Array.of can be used to convert array-like objects into true arrays.

function example() {
    return Array.of(...arguments);
}

const arr = example(1, 2, 3);
console.log(arr);

We convert the arguments object into a true array using Array.of() with the spread operator. This demonstrates how Array.of() can work with array-like objects to create proper arrays.

$ node main.js
[ 1, 2, 3 ]

Source

Array.of - language reference

In this article we have demonstrated how to use the Array.of() method to create arrays in JavaScript.

Author

My name is Jan Bodnar, and I am a passionate programmer with extensive programming experience. I have been writing programming articles since 2007. To date, I have authored over 1,400 articles and 8 e-books. I possess more than ten years of experience in teaching programming.

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