SOURCE

let str2 = "";
let str = "";
function testAwait() {

    return new Promise((resolve) => {
        setTimeout(function () {
            console.log("testAwait");
            resolve(str);
        }, 3000);
    }).then(res => {
        str = "我是变量1"
    })
}

function testAwait2() {
    return new Promise((resolve) => {
        setTimeout(function () {
            console.log("testAwait2");
            resolve();
        }, 1000);
    }).then(res => {
        str2 = str
        console.log(str2)
    })
}
async function helloAsync() {
    await testAwait();
    await testAwait2();
    console.log("helloAsync");
    hello()
}
function hello() {
    console.log("nihao")
}
helloAsync();

// testAwait
// helloAsync

let str2 = "";
let str = "";
function testAwait() {
    
    return new Promise((resolve) => {
        setTimeout(function () {
            console.log("testAwait");
            resolve(str);
        }, 3000);
    }).then(res => {
       str = "我是变量1"
    })
}

function testAwait2() {
    return new Promise((resolve) => {
        setTimeout(function () {
            console.log("testAwait2");
            resolve();
        }, 1000);
    }).then(res => {
        str2 = str
        console.log(str2)
    })
}
async function helloAsync() {
    await testAwait();
    await testAwait2();
    console.log("helloAsync");
    hello()
}
function hello() {
    console.log("nihao")
}
helloAsync();

// testAwait
// helloAsync