fill-range     

Fill in a range of numbers or letters, optionally passing an increment or step to use, or create a regex-compatible range with options.toRegex

Please consider following this project's author, Jon Schlinkert, and consider starring the project to show your ❤️ and support.

Install

Install with npm:

sh
$ npm install --save fill-range

Usage

Expands numbers and letters, optionally using a step as the last argument. _(Numbers may be defined as JavaScript numbers or strings)_.

js
const fill = require('fill-range');
// fill(from, to[, step, options]);

console.log(fill('1', '10')); //=> ['1', '2', '3', '4', '5', '6', '7', '8', '9', '10']
console.log(fill('1', '10', { toRegex: true })); //=> [1-9]|10

Params

• from: {String|Number} the number or letter to start with
• to: {String|Number} the number or letter to end with
• step: {String|Number|Object|Function} Optionally pass a [step](#optionsstep) to use.
• options: {Object|Function}: See all available [options](#options)

Examples

By default, an array of values is returned.

Alphabetical ranges

js
console.log(fill('a', 'e')); //=> ['a', 'b', 'c', 'd', 'e']
console.log(fill('A', 'E')); //=> [ 'A', 'B', 'C', 'D', 'E' ]

Numerical ranges

Numbers can be defined as actual numbers or strings.

js
console.log(fill(1, 5));     //=> [ 1, 2, 3, 4, 5 ]
console.log(fill('1', '5')); //=> [ 1, 2, 3, 4, 5 ]

Negative ranges

Numbers can be defined as actual numbers or strings.

js
console.log(fill('-5', '-1')); //=> [ '-5', '-4', '-3', '-2', '-1' ]
console.log(fill('-5', '5')); //=> [ '-5', '-4', '-3', '-2', '-1', '0', '1', '2', '3', '4', '5' ]

Steps (increments)

js
// numerical ranges with increments
console.log(fill('0', '25', 4)); //=> [ '0', '4', '8', '12', '16', '20', '24' ]
console.log(fill('0', '25', 5)); //=> [ '0', '5', '10', '15', '20', '25' ]
console.log(fill('0', '25', 6)); //=> [ '0', '6', '12', '18', '24' ]

// alphabetical ranges with increments
console.log(fill('a', 'z', 4)); //=> [ 'a', 'e', 'i', 'm', 'q', 'u', 'y' ]
console.log(fill('a', 'z', 5)); //=> [ 'a', 'f', 'k', 'p', 'u', 'z' ]
console.log(fill('a', 'z', 6)); //=> [ 'a', 'g', 'm', 's', 'y' ]

Options

options.step

Type: number (formatted as a string or number)

Default: undefined

Description: The increment to use for the range. Can be used with letters or numbers.

Example(s)

js
// numbers
console.log(fill('1', '10', 2)); //=> [ '1', '3', '5', '7', '9' ]
console.log(fill('1', '10', 3)); //=> [ '1', '4', '7', '10' ]
console.log(fill('1', '10', 4)); //=> [ '1', '5', '9' ]

// letters
console.log(fill('a', 'z', 5)); //=> [ 'a', 'f', 'k', 'p', 'u', 'z' ]
console.log(fill('a', 'z', 7)); //=> [ 'a', 'h', 'o', 'v' ]
console.log(fill('a', 'z', 9)); //=> [ 'a', 'j', 's' ]

options.strictRanges

Type: boolean

Default: false

Description: By default, null is returned when an invalid range is passed. Enable this option to throw a RangeError on invalid ranges.

Example(s)

The following are all invalid:

js
fill('1.1', '2');   // decimals not supported in ranges
fill('a', '2');     // incompatible range values
fill(1, 10, 'foo'); // invalid "step" argument

options.stringify

Type: boolean

Default: undefined

Description: Cast all returned values to strings. By default, integers are returned as numbers.

Example(s)

js
console.log(fill(1, 5));                    //=> [ 1, 2, 3, 4, 5 ]
console.log(fill(1, 5, { stringify: true })); //=> [ '1', '2', '3', '4', '5' ]

options.toRegex

Type: boolean

Default: undefined

Description: Create a regex-compatible source string, instead of expanding values to an array.

Example(s)

js
// alphabetical range
console.log(fill('a', 'e', { toRegex: true })); //=> '[a-e]'
// alphabetical with step
console.log(fill('a', 'z', 3, { toRegex: true })); //=> 'a|d|g|j|m|p|s|v|y'
// numerical range
console.log(fill('1', '100', { toRegex: true })); //=> '[1-9]|[1-9][0-9]|100'
// numerical range with zero padding
console.log(fill('000001', '100000', { toRegex: true }));
//=> '0{5}[1-9]|0{4}[1-9][0-9]|0{3}[1-9][0-9]{2}|0{2}[1-9][0-9]{3}|0[1-9][0-9]{4}|100000'

options.transform

Type: function

Default: undefined

Description: Customize each value in the returned array (or [string](#optionstoRegex)). _(you can also pass this function as the last argument to fill())_.

Example(s)

js
// add zero padding
console.log(fill(1, 5, value => String(value).padStart(4, '0')));
//=> ['0001', '0002', '0003', '0004', '0005']

About

<details> <summary><strong>Contributing</strong></summary>

Pull requests and stars are always welcome. For bugs and feature requests, [please create an issue](../../issues/new).

</details>

<details> <summary><strong>Running Tests</strong></summary>

Running and reviewing unit tests is a great way to get familiarized with a library and its API. You can install dependencies and run tests with the following command:

sh
$ npm install && npm test

</details>

<details> <summary><strong>Building docs</strong></summary>

_(This project's readme.md is generated by verb, please don't edit the readme directly. Any changes to the readme must be made in the [.verb.md](.verb.md) readme template.)_

To generate the readme, run the following command:

sh
$ npm install -g verbose/verb#dev verb-generate-readme && verb

</details>

Contributors

Author

Jon Schlinkert

• GitHub Profile
• Twitter Profile
• LinkedIn Profile

Please consider supporting me on Patreon, or start your own Patreon page!

<a href="https://www.patreon.com/jonschlinkert"> <img src="https://c5.patreon.com/external/logo/become_a_patron_button@2x.png" height="50"> </a>

License

Copyright © 2019, Jon Schlinkert. Released under the [MIT License](LICENSE).

_This file was generated by verb-generate-readme, v0.8.0, on April 08, 2019._