js异步操作顺序执行与并序执行

1、异步操作顺序执行

const uploadArray = () => {
    fileList.value.reduce((previousValue, currentValue) => {
        return upload(currentValue)
    }, Promise.resolve())
}

const upload = async(fileItem) => {
    try {
        const res = await uploadFile(fileItem)
        res.state === 200 ? 
        return Promise.resolve() : 
        return Promise.reject()
    } catch (error) {
        console.log(error);
        return Promise.reject()
    }
}

reduce()方法对数组中的每个元素按序执行一个回调函数，每一次运行回调函数会将先前元素的计算结果作为参数传入
详细参考Array.prototype.reduce()

2、并行执行完所有异步操作后，再继续其他内容

const delPic = async(file) => {
    try {
        const res = await s3DelImg({ fileName: file.fileName, fileId: file.fileId})
        res.state !== 200 ?
        message.error(res.message) : ''
        return Promise.resolve()
    } catch (error) {
        return Promise.resolve()
    }
};

const delList = () => {
    let delList = [1,2,3]
    let proResList = delList.map((item: any) => { return delPic(item) })
    Promise.all(proResList).then(() => {
        getImgList() //接口请求
    })
}

Promise.all(),对传入的promise组成的数组进行检测，数组中promise全部成功resolve()后,.then()执行后续操作