fastrange

A fast range function for JavaScript

Create an array of numbers within a given range. This is an useful alternative for the for loop when using a functional programming style where using map, filter and similar functions are preferred. Fastrange implements the range function known from Python. Fastrange is faster and more lightweight than alternative JavaScript implementations.

Installation

$ npm install fastrange

Usage

Using import, as a ESM module, for use with a bundler like webpack or rollup:

import range from 'fastrange';

As a commonjs module, for use in Node.js:

const range = require('fastrange');

Then:

range(10);
//=> [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]

range(5, 10);
//=> [5, 6, 7, 8, 9]

range(4, 10, 2);
//=> [4, 6, 8]

API

range( [start=0], stop, [step=1] )

Returns an array of numbers dependent of the given parameters.

start

Type: number

Optional, start of the range, by default 0

stop

Type: number

End of the range, this value is not included in the result.

step

Type: number

Optional, step between the numbers in the range, by default 1

Performance

Many different implementations have been tested for perfomance and the fastest across browsers, using array push in a for loop, is being used in fastrange.

• JSPerf range implementations

Tests

npm test

Related

• Python range

License

MIT © 2019 Edwin Martin