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    windowed es-toolkit

    Returns a new array containing snapshots of each window as a window of specified size slides regularly along the array.

    const windows = windowed(arr, size, step?, options?);

    Usage

    windowed(arr, size, step?, options?)

    Use windowed when you want to return an array containing snapshots as a window of specified size slides regularly along an array.

    It's useful for calculating moving averages in time series data analysis, extracting n-grams from strings, or finding specific patterns in arrays. It can also be used for processing data in batch units or implementing sliding window algorithms.

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

// Basic usage - create windows of size 3.
const numbers = [1, 2, 3, 4, 5];
const result = windowed(numbers, 3);
console.log(result); // [[1, 2, 3], [2, 3, 4], [3, 4, 5]]

// Adjust window spacing by specifying step.
const data = [1, 2, 3, 4, 5, 6, 7, 8];
const stepped = windowed(data, 3, 2);
console.log(stepped); // [[1, 2, 3], [3, 4, 5], [5, 6, 7]]

// Can also be used with string arrays.
const words = ['a', 'b', 'c', 'd', 'e'];
const wordWindows = windowed(words, 2);
console.log(wordWindows); // [['a', 'b'], ['b', 'c'], ['c', 'd'], ['d', 'e']]

    Use the partialWindows option if you want to include partial windows.

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

const numbers = [1, 2, 3, 4, 5, 6];

// Without partial windows (default)
const complete = windowed(numbers, 4, 3);
console.log(complete); // [[1, 2, 3, 4]]

// With partial windows
const withPartial = windowed(numbers, 4, 3, { partialWindows: true });
console.log(withPartial); // [[1, 2, 3, 4], [4, 5, 6]]

    Each snapshot is provided in array form, and the last few arrays may have fewer elements than the specified size.

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

const small = [1, 2];

// When window is larger than array
console.log(windowed(small, 5)); // []
console.log(windowed(small, 5, 1, { partialWindows: true })); // [[1, 2], [2]]

    Parameters

    arrreadonly T[]required

    The array to create windows from.

    sizenumberrequired

    The size of each window. Must be a positive integer.

    stepnumberoptional

    The spacing between windows. Must be a positive integer. Default is 1.

    options.partialWindowsbooleanoptional

    Whether to include incomplete windows at the end of the array. Default is false.

    Returns

    An array of windows created with the specified size and spacing.

    T[][]

    Throws

    Throws an error if size or step is not a positive integer.

    Source: es-toolkit

    Re-exported verbatim from es-toolkit. Implementation, edge cases, and performance behavior are owned upstream. This page mirrors the documentation at the pinned version; the linked source is authoritative.