var fn1 = function (a) {

  a = "foo"

  console.log(arguments[0])

}

​

fn1(2)

​

​

var fn2 = function (a) {

  arguments[0] = "bar"

  console.log(a)

}

​

fn2(2)

​

​

var fn3 = function (a) {

  "use strict";

  a = "foo"

  console.log(arguments[0])

}

​

fn3(2)

​

​

var fn4 = function (a = 0) {

  arguments[0] = "bar"

  console.log(a)

}

​

fn4(2)

​

​

var fn5 = function (...args) {

  arguments[0] = "bar"

  console.log(args[0])

}

​

fn5(2)

​

​

var fn6 = function () {

  const [a] = arguments

  arguments[0] = "bar"

  console.log(a)

}

​

fn6(2)

​