超级解构

let a = {
        b = {

            c:1
        }
    }
    console.log(a.b.c)  //1

    let {b} = a
　　 相当于 b = a.b
    console.log(b.c) //1

    let { b: { c } } = a
　　b来源于a.b
　　c来源于a.b.c

    console.log(c)  //1