arrow function explanation

arrow-fns.js

// this has a block, needs a return statement
const fn1 = () => {
  return 1
}

// this does the same as the above,
// if you're returning something without other stuff, no need for curly braces
const fn2 = () => 1

// adding parentheses is just a stylistic choice, it does the same thing
const fn3 = () => (
  1
)

// if you use curly braces, that's the block form.
// without `return`, you'll have a floating value that does nothing
const fn4 = () => {
  1
}