Writing it short with an arrow function

01 / 04

If it means the same, shorter is better

A function expression was written const name = function() { };. That word function is fairly long to type every time.

So there is another way of writing it, called an arrow function. It uses =>, which looks like an arrow, hence the name.

02 / 04

Two steps, that is all.

The two below behave exactly the same. Have a look side by side.

const greetA = function() {  console.log("good morning");};const greetB = () => {  console.log("good morning");};greetA();greetB();

Result

good morning
good morning

03 / 04

What you can write inside the { } has not changed. Loops and branches go in just as they always did.

The call is still name(). Take it that only the look of the definition has changed.

const countDown = () => {  for (let i = 3; i >= 1; i--) {    console.log(i);  }  console.log("go");};countDown();

Result

3
2
1
go

04 / 04

Because an arrow function is short, you see this form very often in real code. Being able to read it makes other people's code much clearer.

The ; after the final } is easy to forget, so watch for it. It is a statement that puts a value in a variable, after all.

Right then, let us practise rewriting.