is-any-letter

A small module to detect letters by checking if it has a lowercase and uppercase version.

Installation

$ npm install is-any-letter --save

Usage

In this module, a letter is any character that has an uppercase and lowercase version, so some special characters that are only lowercase or uppercase will return false.

const letter = require('is-any-letter')
 
// tests if a single charcter is a letter
letter.isLetter('A') // true
 
// tests if a string only contains a letter
letter.onlyLetters('Aβçdéfϱ') // true

Adding allowed symbols or character

It's possible to add any symbol or character to the accepted ones by adding a string with allowed characters as second argument.

letter.isLetter('*', '*_-()') // true
letter.onlyLetters('A-β*ç_d(éf)ϱ', '*_-()') // true

Test

$ npm test