ES6语法糖

var events = { listeners, listen }

等同

var events = {
  listeners: listeners,
  listen: listen
}

var expertise = "name"
var person = {
    b:1
}
person[expertise] = "aa"

等同

var expertise = 'name'
var person = {
  b:1,
  [expertise]:"aa"
}

var emitter = {
  events: {},
  on: function (type, fn) {
  }
}

等同

var emitter = {
  events: {},
  on(type, fn) {
  }
}

---

var example = function (parameters) {
  // function body
}

等同

var example = (parameters) => {
  // function body
}

当只有一个参数时,等同

var example = parameters => {
  return parameters * 2
}

直接return时,等同

var example = 
parameters => parameters * 2

---

var pseudonym = character.pseudonym

等同

var { pseudonym } = character

---

var alias = character.pseudonym

等同

var { pseudonym: alias } = character

---

var gender = character.metadata.gender

等同

var { metadata: { gender } } = character

---

var names = ['James', 'L.']
var [ firstName = 'John', , lastName = 'Doe' ] = names

等同

var names = ['James', 'L.'];
var firstName = names[0]||'John';
var lastName = names[2]||'Doe';

---

var left = 5, right = 7;
var aux = left
left = right
right = aux

等同

var left = 5, right = 7;
[left, right] = [right, left]

---

function join() {
  var list = Array.prototype.slice.call(arguments)
  return list.join(', ')
}
join('first', 'second', 'third')

等同

function join(...list) {
  return list.join(', ')
}
join('first', 'second', 'third')