Negative array index support array[-1] using ES2015 Proxy

JavaScript doesn't natively support the use of a negative index to get items backwards from the end, but with ES2015 Proxy it's possible. Take a look at the source to see how simple it is to implement and read this short article about it.

Note: With Node.js 16.6.0, you can now use Array#at() instead of this package.

Install

$ npm install negative-array

Usage

import negativeArray from 'negative-array';
// Adds negative array index support to any given array
const unicorn = negativeArray(['🐴', '🎂', '🌈']);
// Get the last item by using a negative index
console.log(unicorn[-1]);
//=> '🌈'
// OMG, YES!

Related

• on-change - Watch an object or array for changes (Uses Proxy too)
• known - Allow only access to known object properties (Uses Proxy too)