Javascript range utility

Features

• Use iterator internally.
• Have optional step and inclusive parameter.

Install

yarn add rrjx

import range from 'rrjx'
// or
const range = require('rrjx')

Usage

Exported type

declare function range(startOrCount: number, end?: number, step?: number, inclusive?: boolean): Generator<number, void, unknown>;
export default range;

Supported call patterns:

range(count) // [0, count - 1)
range(start, end) // [start, end)
range(start, end, step, false) // [start, start + step, start + 2 * step, ..., end)
range(start, end, step, true) // [start, start + step, start + 2 * step, ..., end]

Usage Samples

• For all elements of an array: for (const idx of range(arr.length)) console.log(arr[idx]).
• Same as above but in the reversed order: for (const idx of range(arr.length -1, 0, -1, true)) console.log(arr[idx]).
• Generate an array [0, 1, 2, 3]: [...range(4)].
• Forever loop: for (const _ of range(Infinity)) if (cond()) break.
• If end > start (step >= 0), do nothing: for (const i of range(2, 1)) console.log(i).