消耗等待的结果并返回等待的结果之间有什么区别？
我对以下两个代码片段感到有些困惑：
async function f() {
let promise = new Promise((resolve, reject) => {
setTimeout(() => resolve("done!"), 1000)
});
let result = await promise; // wait until the promise resolves (*)
return result;
}
console.log(f()); //prints Promise { <pending> } at once then wait for 1 second before terminating
我
async function f() {
let promise = new Promise((resolve, reject) => {
setTimeout(() => resolve("done!"), 1000)
});
let result = await promise; // wait until the promise resolves (*)
console.log(result);
}
f(); //waits for 1 second and prints done! before terminating
期望上面的两个代码片段产生相同的结果，例如打印！ 1秒钟后到达控制台。是什么使第一个代码段返回
I am a bit confused by the two following code snippets:
async function f() {
let promise = new Promise((resolve, reject) => {
setTimeout(() => resolve("done!"), 1000)
});
let result = await promise; // wait until the promise resolves (*)
return result;
}
console.log(f()); //prints Promise { <pending> } at once then wait for 1 second before terminating
And
async function f() {
let promise = new Promise((resolve, reject) => {
setTimeout(() => resolve("done!"), 1000)
});
let result = await promise; // wait until the promise resolves (*)
console.log(result);
}
f(); //waits for 1 second and prints done! before terminating
I was expecting the two code snippets above to produce the same result, e.g. print done! to the console after 1 second. What made the first code snippet return
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两个代码片段在同一点返回。
等待关键字在RHS上得到承诺时，它使其属于睡眠的功能直到该诺言解决。同时，调用功能获得了
f返回的承诺，并继续运行。这就是使用
async函数的重点：当他们处理某些异步时，它们不会阻止。Both code snippets return at the same point. The
awaitkeyword, when it gets a promise on the RHS, makes the function it belongs to go to sleep until that promise settles.Meanwhile, the calling function gets the promise returned by
fand continues running.That's the point of using
asyncfunctions: They don't block when they are dealing with something asynchronous.