[TOC] **箭頭函數** ~~~ var sum = (a, b) => a+b; sum(1, 2) 3 ~~~ **對象里函數優化** 對象是這個 ~~~ const p = { name: "jack", age: 21, sayHello: function() { console.log("hello"); } } ~~~ 可以簡寫成 ~~~ const a = { name: "jack", age: 21, sayHello() { console.log("hello"); } } a.sayHello() VM455:5 hello ~~~ **方法里參數對象優化** ~~~ const hello = function(person) { console.log(person.name, person.age); } ~~~ 可以改成 ~~~ const hello = ( {name, age} ) => console.log(name, age); ~~~