count-to-6/lib/exercises/arrow_functions_part_1/solution/solution.js

An intro to some ES6 features via a set of self-guided workshops.

var inputs = process.argv.slice(2);
var result = inputs.map(s => s[0])
                   .reduce((soFar, s) => soFar + s);

console.log(`[${inputs}] becomes "${result}"`);