For AI agents: the complete documentation index is available at /llms.txt, the full documentation bundle is available at /llms-full.txt, and this page is available as Markdown at /reference/math/rangeRight.md.
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    rangeRight es-toolkit

    Creates an array of numbers in reverse order within a specified range and step.

    const numbers = rangeRight(end);
const numbers = rangeRight(start, end, step?);

    Usage

    rangeRight(end)

    Use rangeRight when you need a consecutive array of numbers in reverse order from the end value to 0. It's like range but the result comes from the back.

    import { rangeRight } from 'es-toolkit/math';

// Create an array from 3 to 0 in reverse order.
const numbers1 = rangeRight(4);
console.log(numbers1); // [3, 2, 1, 0]

// Reverse indices of an array
const items = ['a', 'b', 'c', 'd', 'e'];
const reverseIndices = rangeRight(items.length);
reverseIndices.forEach(i => {
  console.log(items[i]); // Outputs 'e', 'd', 'c', 'b', 'a' in order
});

    Parameters

    endnumberrequired

    The end value (exclusive). Starts from 0.

    Returns

    Returns a reverse array of numbers generated from the end value to 0.

    number[]

    rangeRight(start, end, step?)

    Use rangeRight when you need a consecutive array of numbers in reverse order with a specified start value, end value, and step. It's like range but the result comes from the back.

    import { rangeRight } from 'es-toolkit/math';

// Create an array from 4 to 1 in reverse order.
const numbers2 = rangeRight(1, 5);
console.log(numbers2); // [4, 3, 2, 1]

// Create an array from 15 to 0 with decrements of 5.
const numbers3 = rangeRight(0, 20, 5);
console.log(numbers3); // [15, 10, 5, 0]

// Can also go in the negative direction.
const numbers4 = rangeRight(-5, 0, 1);
console.log(numbers4); // [-1, -2, -3, -4, -5]

// Can go from smaller to larger numbers.
const numbers5 = rangeRight(5, 0, -1);
console.log(numbers5); // [1, 2, 3, 4, 5]

    Useful when you need reverse order for countdowns or pagination.

    import { rangeRight } from 'es-toolkit/math';

// Create a countdown
const countdown = rangeRight(0, 11);
console.log(countdown); // [10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0]

// Pagination from last page to first page
const pageNumbers = rangeRight(1, 11);
console.log(pageNumbers); // [10, 9, 8, 7, 6, 5, 4, 3, 2, 1]

    Parameters

    startnumberrequired

    The start value. Included in the result array.

    endnumberrequired

    The end value. Not included in the result array.

    stepnumberoptional

    The increment between each number. Must be a non-zero integer. Defaults to 1.

    Returns

    Returns a reverse array of numbers generated with the specified range and step.

    number[]

    Throws

    • Throws an error if step is 0 or not an 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.