顺序执行promise

main.js

const arr = []

Array(5).fill(0).forEach((value, index) => {
  arr.push(promiseFunc(index))
})

// queue(arr)

//船新解法
arr.reduce((pro,next)=> pro.then(next), Promise.resolve())

promise.js

//生成待执行promise函数
function promiseFunc(index) {
    return function () {
        return new Promise((resolve, reject) => {
            setTimeout(() => {
                console.log(index)
                resolve(index)
            }, 1000)
        })
    }
}

async function queue(list) {
    let index = 0
    while (index >= 0 && index < list.length) {
        await list[index]()
        index++
    }
}