hoisting.js

var scope = "global"

function fn () {
  console.log(scope)
  var scope = "local"
  console.log(scope)
}

function fn2 () {
  console.log(scope)
}

fn() // => undefined, local
fn2() // => global


// fn equals to following function
function fn3 () {
  var scope
  console.log(scope)
  scope = "local"
  console.log(scope)
}