js promise 同步異步數據展示問題？

Question

getIanMediumList().then(res => {
   this.mixItems = this.mixItems.concat(res.items)
   console.log('A': this.mixItems)
})
getGreenMediumList().then(res => {
   this.mixItems = this.mixItems.concat(res.items)
   console.log('B': this.mixItems)
})
console.log('C': this.mixItems)

Ａ跟Ｂ都可以展示出數據
但是Ｃ展示不出來，會是空的
如何等兩個都完成後，讓Ｃ取得數據？

Answer 1

有异步了当然就得继续异步……

let p1 = getIanMediumList().then(res => {
   this.mixItems = this.mixItems.concat(res.items)
   console.log('A': this.mixItems)
})
let p2 = getGreenMediumList().then(res => {
   this.mixItems = this.mixItems.concat(res.items)
   console.log('B': this.mixItems)
})

Promise.all([p1, p2]).then(() => {
    console.log('C': this.mixItems)
})