Javascript javascript异步/等待不起作用
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javascript async/await not working
提问by noobie
I have a specific case where I need to wait for a async calls result before continuing. I am using the async/await keywords, but not having any luck. Any help appreciated.
我有一个特定情况，我需要在继续之前等待异步调用结果。我正在使用 async/await 关键字，但没有任何运气。任何帮助表示赞赏。
This is my attempt to try getting it to work, the numbers should be in numerical order.
这是我尝试让它工作的尝试，数字应该按数字顺序排列。
function sleep(ms) {
return new Promise(resolve => setTimeout(resolve, ms));
}
async function demo() {
document.writeln('2...');
await sleep(2000);
document.writeln('3...');
}
document.writeln('1...');
demo();
document.writeln('4.');采纳答案by Lee Han Kyeol
You should use .then()after async function.
您应该使用.then()after async function。
function sleep(ms) {
return new Promise(resolve => setTimeout(resolve, ms));
}
async function demo() {
document.writeln('2...');
await sleep(2000);
document.writeln('3...');
}
document.writeln('1...');
demo().then(() => {
document.writeln('4.');
});回答by Danny Sullivan
The async function will return a Promise, so you need to await the call to demo
异步函数将返回 a Promise，因此您需要等待对demo
const sleep = (ms) => new Promise(resolve => setTimeout(resolve, ms))
const demo = async() => {
console.log('2...')
await sleep(2000)
console.log('3...')
}
const blah = async() => {
console.log('1...')
await demo()
console.log('4.')
}
blah()