unshift

The unshift() function adds one or more elements to the beginning of the array and returns an enriched copy.

Interactive example

Syntax

Classic signature

function unshift<
	GenericElement extends unknown
>(
	input: readonly GenericElement[],
	element: NoInfer<GenericElement>,
	...elements: NoInfer<GenericElement>[]
): GenericElement[]

Curried signature

function unshift<
	GenericElement extends unknown
>(
	element: NoInfer<GenericElement>
): (input: readonly GenericElement[]) => GenericElement[]

Parameters

• input: Source array.
• element, ...elements: Values inserted at the beginning (in the order provided).

Return value

A new array whose prefix matches the added values, followed by the former content.

See also

• shift - Removes the first element
• push - Adds at the end of the array

Sources

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