async 修饰符对微观队列的插入顺序存在特殊影响吗？

Question

async1().then(() => {
    console.log('async1 call')
})
sync2().then(()=>{
    console.log('sync2 call')
})
async function async1() {
    return Promise.resolve(new Promise(resolve => {
            console.log('async1 resolve')
            resolve()
        })
    )
}
function sync2() {
    return Promise.resolve(new Promise(resolve => {
            console.log('sync2 resolve')
            resolve()
        })
    )
}
new Promise(resolve => {
    console.log('Promise3 resolve')
    resolve()
}).then(() => {
    console.log('Promise3 call')
})
console.log('script end')

上面的代码输出顺序为：

这是为啥呢？个人理解按微观队列的先进先出原则,'async1 call' 应该是在 'sync2 call' 之前输入才对啊，我发现只要去掉async1方法的async修饰符，一切就又正常了。是async修饰符对微观队列的插入顺序起了什么特殊影响吗？有没有哪位大佬帮小弟解答下

Answer 1

关键不在于 async，而在于 await

来看看「理解 JavaScript 的 async/await」