Easy number range numbers with steps

Minimal and handy utility to generate ranges of numbers with start, end and optional steps or jumps!

Use cases

• You need a simple, straightforward solution to generate numbers for an array to end on a determined number;
• Your array needs steps between numbers;
• Your array should be declarative, i.e. end on the defined number. If you explicit ask for 10, 10 should be the last number unless:
  • If you pass and end parameter and is outside of the step, it will yield only up to steps you need to ensure the rule, otherwise you would get an result not in the step rule defined.

Params

| Parameter | Description | |:---------: |---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | first | Required Number The first parameter defines the limit of the numbers returned. If you want a list from 0 up to x, just pass x. X will be included unless other rules apply. | | second | Optional Number The second parameter defines the start. As usual all arrays start with the offset from the start, i.e. 0, with this parameter will decide a number that will be the starting point. | | third | Optional Number The thir parameter defines a step rule. This rules that precedence over the first one. If you want to generate numbers until x, with a gap or steps between them of 3, and the end number is greater than the step rule, it will be not returned, but will be used as a limit to the numbers returned. |

How to use

You always should use with the spread operator.

import { range } from "easy-range-numbers-with-steps";

const arrWithEnd = [...range(5)];

// arrWithEnd will be an array, with [0,1,2,3,4,5]

const arrWithEndAndStart = [...range(5, 10)];

// arrWithEndAndStart will be an array, with [5, 6, 7, 8, 9, 10]

const arrWithEndAndStartAndStep = [...range(10, 0, 2)];

// arrWithEndAndStart will be an array, with [0, 2, 4, 6, 8, 10]

const arrWithEndAndStartAndStep2 = [...range(11, 0, 2)];

// arrWithEndAndStart will be an array, with [0, 2, 4, 6, 8, 10]! 11 is the end, but outside of the desired steps!

If you use directly we'll just get an object with the Symbol and the Generator function. If this is what you want, that's ok! Just an friendly warning if you do not know what this means and you start to get "errors" for misuse.

import { range } from "easy-range-numbers-with-steps";

const arr = range(5);

// You will not get an array! If you do a console.info(arr):
// { [Symbol(Symbol.iterator)]: [GeneratorFunction: generateRange] }

Purpose

This is a minimal lib. No external dependencies, feel free to just copy if necessary to your project. It was created for a specific need and I wanted to share with someone with the same use-cases. Arrays are the bread and butter of web apps and is always handy use helper functions.

Unit tests

MIT License

Copyright (c) 2020 — 2022 Ibrahim Cesar

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.