sampleSize

Returns a new array of randomly selected elements with the specified size.

const sampled = sampleSize(array, size);

Reference

sampleSize(array, size)

Use sampleSize when you want to randomly sample multiple elements from an array. It uses Floyd's algorithm to efficiently generate random samples without duplicates. It's useful for extracting samples in surveys or randomly selecting multiple items in games.

import { sampleSize } from 'es-toolkit/array';

// Randomly select 3 from a number array.
const numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
const randomNumbers = sampleSize(numbers, 3);
// Returns: [2, 7, 9] (example, actually random)

// Randomly select 2 from a string array.
const fruits = ['apple', 'banana', 'cherry', 'date', 'elderberry'];
const randomFruits = sampleSize(fruits, 2);
// Returns: ['cherry', 'apple'] (example, actually random)

You can sample with various sizes.

import { sampleSize } from 'es-toolkit/array';

const items = ['a', 'b', 'c', 'd', 'e'];

// Select 1 element
const single = sampleSize(items, 1);
// Returns: ['c'] (example)

// Select same as entire array size (shuffle effect)
const all = sampleSize(items, 5);
// Returns: ['b', 'd', 'a', 'e', 'c'] (example)

// Select empty array
const none = sampleSize(items, 0);
// Returns: []

Parameters

• array (readonly T[]): The array to sample from.
• size (number): The number of elements to select.

Returns

(T[]): Returns a new array consisting of randomly selected elements.

Throws

Throws an error if size is greater than the length of the array.