SOURCE

const loanProductQuery = () => {
    return Promise.resolve([1, 2, 3])
}
const loanStateQuery = num => {
    return new Promise((resolve, reject) => {
        setTimeout(() => {
            if (num !== 2) {
                resolve(num * num)
            } else {
                reject(new Error('num not specified'))
            }
        }, 1000)
    })
}
async function test() {
    let nums = await loanProductQuery()

    // nums.forEach(async item => {
    //     var res = await loanStateQuery(item)
    //     console.log(res)
    // })

    for (let i = 0; i < nums.length; i++) {
        (async () => {
            const res = await loanStateQuery(nums[i])
            console.log(res)
        })(nums[i])
    }
}
test()