Discussion on: Javascript(ES6) Arrow Functions in a simple way:

So I'm not convinced with defining functions with const you claim it's shorter - but that's because you've define the function version in a very odd way in your example.

const sayHello = (firstName,lastName) => { // 41 characters

Compared with

function sayHello(firstName,lastName) { // 39 characters

Plus I know the second one is a function. The first one is a const, not hoisted so I have to start caring about order and reading deep into the line to realise it is a function.

For me, the reason to use an arrow function is for capturing this or for defining an anonymous inline function:

   someArray.filter(a=>a.id.startsWith('$')) // this IS shorter and clearer