JavaScript Array copyWithin()

Copy the first two array elements to the last two array elements:

const fruits = ["Banana", "Orange", "Apple", "Mango"];
fruits.copyWithin(2, 0);

Copy the first two array elements to the third and fourth position:

const fruits = ["Banana", "Orange", "Apple", "Mango", "Kiwi"];
fruits.copyWithin(2, 0, 2);

Description

The copyWithin() method copies array elements to another position in the array.

The copyWithin() method overwrites the existing values.

The copyWithin() method does not add items to the array.

array.copyWithin( target, start, end)

Parameter	Description
target	Required. The index (position) to copy the elements to.
start	Optional. The start index (position). Default is 0.
end	Optional. The end index (position). Default is the array length.

Type	Description
Array	The changed array.

copyWithin() is an ECMAScript6 (ES6) feature.

ES6 (JavaScript 2015) is supported in all modern browsers:


Chrome	Edge	Firefox	Safari	Opera
Yes	Yes	Yes	Yes	Yes

copyWithin() is not supported in Internet Explorer 11 (or earlier).