ES2015
Array#findIndex()
ponyfill
$ npm install --save array-find-index
const arrayFindIndex = require('array-find-index'); arrayFindIndex(['rainbow', 'unicorn', 'pony'], x => x === 'unicorn'); //=> 1
Same as Array#findIndex()
, but with the input array as the first argument.
MIT © Sindre Sorhus