Vue中的同步调用和异步调用方式

async functionbasicDemo() {
    let result = await Math.random();
    console.log(result);
}
basicDemo();
// 0.6484863241051226//Promise {[[PromiseStatus]]: "resolved", [[PromiseValue]]: undefined}

async functiondemo01(){
    return 123;
}
demo01().then(val=> {
    console.log(val);// 123});

functionnotAsyncFunc(){
    await Math.random();
}
notAsyncFunc();//Uncaught SyntaxError: Unexpected identifier

functionsleep(second){
    return new Promise((resolve, reject) => {
        setTimeout(()=> {
            resolve(' enough sleep~');
        }, second);
    })
}functionnormalFunc(){
    console.log('normalFunc');
}async functionawaitDemo(){
    await normalFunc();
    console.log('something, ~~');
    let result = await sleep(2000);
    console.log(result);// 两秒之后会被打印出来}
awaitDemo()

functionsleep(second, param){
    return new Promise((resolve, reject) => {
        setTimeout(()=> {
            resolve(param);
        }, second);
    })
}async functiontest(){
    let result1 = await sleep(2000, 'req01');
    let result2 = await sleep(1000, 'req02' + result1);
    let result3 = await sleep(500, 'req03' + result2);
    console.log(`${result3}${result2}${result1}`);
}
test();

functionsleep(second){
    return new Promise((resolve, reject) => {
        setTimeout(()=> {
            reject('want to sleep~');
        }, second);
    })
}async functionerrorDemo(){
    let result = await sleep(1000);
    console.log(result);
}
errorDemo();// VM706:11 Uncaught (in promise) want to sleep~// 为了处理Promise.reject 的情况我们应该将代码块用 try catch 包裹一下async functionerrorDemoSuper(){
    try {
        let result = await sleep(1000);
        console.log(result);
    } catch (err) {
        console.log(err);
    }
}
errorDemoSuper();// want to sleep~

functionsleep(second){
    return new Promise((resolve, reject) => {
        setTimeout(()=> {
            resolve('request done! ' + Math.random());
        }, second);
    })
}async functionbugDemo(){
    await sleep(1000);
    await sleep(1000);
    await sleep(1000);
    console.log('clear the loading~');
}
bugDemo();

async functioncorrectDemo(){
    let p1 = sleep(1000);
    let p2 = sleep(1000);
    let p3 = sleep(1000);
    await Promise.all([p1, p2, p3]);
    console.log('clear the loading~');
}
correctDemo();// clear the loading~