JavaScript Array with() Method

The Array.with() method is a modern JavaScript feature introduced in ECMAScript 2023 (ES14). It creates a shallow copy of an array and replaces the element at a specified index with a new value, leaving the original array unchanged. This makes it a non-mutating alternative for modifying elements in an array.

Syntax

let newArray = arr.with(index, value);

Parameters

Parameter	Description
index	(Required) The index of the element to replace. Can be positive or negative.
value	(Required) The new value to set at the specified index.

Return Value

The method returns a new array with the specified index replaced by the provided value. If the index is out of range, the method throws a RangeError.

Example 1: Replacing an Element

let arr = [10, 20, 30, 40, 50];
let newArr = arr.with(1, 15);
console.log(newArr); 
// Output: [ 10, 15, 30, 40, 50 ]

Example 2: Using Negative Indices

let arr = [10, 20, 30, 40, 50];
let newArr = arr.with(-1, 99);
console.log(newArr); 
// Output: [ 10, 20, 30, 40, 99 ]

Example 3: Modifying Nested Arrays

let arr = [[1, 2], [3, 4], [5, 6]];

let newArr = arr.with(1, [7, 8]);
console.log(newArr); 
// Output: [[1, 2], [7, 8], [5, 6]]

Supported Browsers

Browser	Support
Chrome	110+
Firefox	109+
Safari	16.4+
Edge	110+
Opera	96+
Internet Explorer	Not Supported