set

The set() function replaces the value at a given index and returns a new array without modifying the original.

Interactive example

Syntax

Classic signature

function set<
	GenericElement extends unknown
>(
	input: readonly GenericElement[],
	index: number, 
	element: GenericElement
): GenericElement[];

Curried signature

function set<
	GenericElement extends unknown
>(
	index: number, 
	element: GenericElement
): (input: readonly GenericElement[]) => GenericElement[];

Parameters

• input: The source array.
• index: The index to replace (indexes are normalized with a modulo on length, so out-of-range values target an existing position).
• element: The new value.

Return value

A new array whose targeted element (after index normalization) matches element. Other elements are copied as is.

See also

• fill - Fills a portion of the array
• copyWithin - Copies a segment within the same array

Sources

• MDN Web Docs - Array.prototype.with()