Array.prototype.slice()

The slice() method returns a shallow copy of a portion of an array into a new array object selected from start to end (end not included) where start and end represent the index of items in that array. The original array will not be modified.

Syntax

slice()
slice(start)
slice(start, end)

Parameters

• start optional
  • : Zero-based index at which to start extraction, converted to an integer.
    • Negative index counts back from the end of the array — if start < 0, start + array.length is used.
    • If start < -array.length or start is omitted, 0 is used.
    • If start >= array.length, nothing is extracted.
• end optional
  • : Zero-based index at which to end extraction, converted to an integer. slice() extracts up to but not including end.
    • Negative index counts back from the end of the array — if end < 0, end + array.length is used.
    • If end < -array.length, 0 is used.
    • If end >= array.length or end is omitted, array.length is used, causing all elements until the end to be extracted.
    • If end is positioned before or at start after normalization, nothing is extracted.

Return value

A new array containing the extracted elements.

Description

The slice() method is a copying method. It does not alter this but instead returns a shallow copy that contains some of the same elements as the ones from the original array.

The slice() method preserves empty slots. If the sliced portion is sparse, the returned array is sparse as well.

The slice() method is generic. It only expects the this value to have a length property and integer-keyed properties.