slice (Lodash Compatibility)

Use Array.prototype.slice

This slice function operates slowly due to null or undefined handling and special processing of sparse arrays. JavaScript's native Array.prototype.slice method is faster and more standardized.

Instead, use the faster and more modern Array.prototype.slice.

Slices a portion of an array to create a new array.

const sliced = slice(array, start, end);

Reference

slice(array, start, end)

Use slice when you need only a specific portion of an array. It creates a new array containing elements from the start position up to, but not including, the end position.

import { slice } from 'es-toolkit/compat';

// Slice from index 1 to 2
slice([1, 2, 3, 4], 1, 3);
// Returns: [2, 3]

// Use negative indices
slice([1, 2, 3, 4], -2);
// Returns: [3, 4]

// Specify only start position
slice([1, 2, 3, 4], 2);
// Returns: [3, 4]

null or undefined is handled as an empty array.

import { slice } from 'es-toolkit/compat';

slice(null); // []
slice(undefined); // []

When processing sparse arrays, empty slots are filled with undefined.

import { slice } from 'es-toolkit/compat';

const sparse = new Array(3);
sparse[1] = 'b';
slice(sparse);
// Returns: [undefined, 'b', undefined]

Using negative indices calculates from the end of the array.

import { slice } from 'es-toolkit/compat';

slice([1, 2, 3, 4, 5], -3, -1);
// Returns: [3, 4]

Parameters

• array (ArrayLike<T> | null | undefined): The array to slice.
• start (number, optional): The start position. Negative values calculate from the end. The default is 0.
• end (number, optional): The end position (not included). Negative values calculate from the end. The default is the array's length.

Returns

(T[]): Returns a new array containing elements from start up to, but not including, end.