Arrow functions

ES6 introduced the arrow syntax of writing function expressions:

const addOne = (val) => { return ++val }

To further complicate matters, we can omit the parentheses around val because there's only one parameter:

const addOne = val => { return ++val }

The main difference between arrow functions and expressions is centered around lexical scoping. We touched on scope with hoisting, and we'll discuss it in more detail in the next chapter.