JavaScript toSorted method
last modified April 4, 2025
In this article we show how to sort arrays using the toSorted method
in JavaScript.
Array sorting
Array sorting is the operation of arranging elements in a specific order. The
toSorted method creates a new array with elements sorted in
ascending order by default. Unlike sort, it doesn't modify the
original array.
This method was introduced in ECMAScript 2023 as a safer alternative to
sort. It maintains immutability by returning a new sorted array
while leaving the original array unchanged. This is particularly useful in
functional programming.
The toSorted method can take an optional compare function as an
argument. This function determines the sorting order of elements. Without a
compare function, elements are converted to strings and sorted by UTF-16 code
units.
Basic toSorted example
The following example demonstrates the basic usage of the toSorted
method.
const numbers = [3, 1, 4, 1, 5, 9]; const sortedNumbers = numbers.toSorted(); console.log(numbers); // Original array unchanged console.log(sortedNumbers); // New sorted array
We create an array of numbers and sort them. The original array remains unmodified. The toSorted() method returns a new array with elements sorted in ascending order.
$ node main.js [ 3, 1, 4, 1, 5, 9 ] [ 1, 1, 3, 4, 5, 9 ]
Sorting strings
The toSorted method works with string elements as well.
const fruits = ['banana', 'apple', 'cherry', 'date']; const sortedFruits = fruits.toSorted(); console.log(fruits); console.log(sortedFruits);
We sort an array of strings alphabetically. By default, string comparison is case-sensitive and based on UTF-16 code unit values. The original array remains unchanged.
$ node main.js [ 'banana', 'apple', 'cherry', 'date' ] [ 'apple', 'banana', 'cherry', 'date' ]
Using a compare function
The toSorted() method can take a compare function for custom sorting.
const numbers = [10, 5, 8, 2, 1]; const descending = numbers.toSorted((a, b) => b - a); console.log(numbers); console.log(descending);
We sort numbers in descending order using a compare function. The function returns a positive, negative, or zero value to determine the sort order. The original array is preserved.
$ node main.js [ 10, 5, 8, 2, 1 ] [ 10, 8, 5, 2, 1 ]
Sorting objects by property
We can sort arrays of objects using a property-based compare function.
const users = [
{ name: 'John', age: 25 },
{ name: 'Alice', age: 30 },
{ name: 'Bob', age: 20 }
];
const byAge = users.toSorted((a, b) => a.age - b.age);
console.log(byAge);
We sort an array of objects by their age property. The compare function extracts the age values for comparison. This creates a new sorted array without modifying the original.
$ node main.js
[
{ name: 'Bob', age: 20 },
{ name: 'John', age: 25 },
{ name: 'Alice', age: 30 }
]
Case-insensitive string sorting
For case-insensitive sorting, we need a custom compare function.
const words = ['Apple', 'banana', 'cherry', 'Date'];
const caseInsensitive = words.toSorted((a, b) =>
a.localeCompare(b, undefined, { sensitivity: 'base' })
);
console.log(words);
console.log(caseInsensitive);
We sort strings case-insensitively using localeCompare with the
base sensitivity option. This treats uppercase and lowercase letters as
equivalent. The original array remains unchanged.
$ node main.js [ 'Apple', 'banana', 'cherry', 'Date' ] [ 'Apple', 'banana', 'cherry', 'Date' ]
Source
Array toSorted - language reference
In this article we have demonstrated how to use the toSorted() method to sort arrays in JavaScript while preserving the original array.