Array.prototype.toSorted()
Baseline 2023
Newly available
Since July 2023, this feature works across the latest devices and browser versions. This feature might not work in older devices or browsers.
The toSorted()
method of Array
instances is the copying version of the sort()
method. It returns a new array with the elements sorted in ascending order.
Syntax
toSorted()
toSorted(compareFn)
Parameters
compareFn
Optional-
A function that determines the order of the elements. If omitted, the array elements are converted to strings, then sorted according to each character's Unicode code point value. See
sort()
for more information.
Return value
A new array with the elements sorted in ascending order.
Description
See sort()
for more information on the compareFn
parameter.
When used on sparse arrays, the toSorted()
method iterates empty slots as if they have the value undefined
.
The toSorted()
method is generic. It only expects the this
value to have a length
property and integer-keyed properties.
Examples
Sorting an array
const months = ["Mar", "Jan", "Feb", "Dec"];
const sortedMonths = months.toSorted();
console.log(sortedMonths); // ['Dec', 'Feb', 'Jan', 'Mar']
console.log(months); // ['Mar', 'Jan', 'Feb', 'Dec']
const values = [1, 10, 21, 2];
const sortedValues = values.toSorted((a, b) => a - b);
console.log(sortedValues); // [1, 2, 10, 21]
console.log(values); // [1, 10, 21, 2]
For more usage examples, see sort()
.
Using toSorted() on sparse arrays
Empty slots are sorted as if they have the value undefined
. They are always sorted to the end of the array and compareFn
is not called for them.
console.log(["a", "c", , "b"].toSorted()); // ['a', 'b', 'c', undefined]
console.log([, undefined, "a", "b"].toSorted()); // ["a", "b", undefined, undefined]
Calling toSorted() on non-array objects
The toSorted()
method reads the length
property of this
. It then collects all existing integer-keyed properties in the range of 0
to length - 1
, sorts them, and writes them into a new array.
const arrayLike = {
length: 3,
unrelated: "foo",
0: 5,
2: 4,
3: 3, // ignored by toSorted() since length is 3
};
console.log(Array.prototype.toSorted.call(arrayLike));
// [4, 5, undefined]
Specifications
Specification |
---|
ECMAScript Language Specification # sec-array.prototype.tosorted |
Browser compatibility
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