为什么函数 A 不能捕获函数 B 抛出的错误

Question

我正在 JavaScript 中进行尝试和捕捉练习。

这是我的代码

function getTime1() {
  return new Promise((resolve, reject) => {
    setTimeout(() => {
      resolve(11111);
    }, 1000);
  });
}

function getTime2() {
  return new Promise((resolve, reject) => {
    setTimeout(() => {
      resolve(22222);
    }, 1000);
  });
}

async function funB() {
  // try {
  let b = await getTime2();
  throw "B error";
  // } catch (e) {
  //   console.log("this" + e);
  // }
}

async function funA() {
  try {
    let a = await getTime1();
    funB();
  } catch (e) {
    console.log("that" + e);
  }
}
funA();

这是结果

Uncaught (in promise) B error

我想知道为什么funb和Funa中没有catch。谢谢

Answer 1

据我了解 try/catch 不适用于异步 :

"Because errorTest is async, it will always return a promise and will never begin execution exactly where you call it: it is asynchronous. errorTest returns, and you exit the try block, before a single line of code within errorTest is run. Therefore, your catch block will never fire, because nothing in errorTest would synchronously throw an exception."

来源：

因为异步将 return 一个 Promise，我相信你需要在 Promise 本身上使用 catch

funB().then((result) => {
    console.log(result);
}).catch((error) => {
    console.error(error);
});

为什么函数 A 不能捕获函数 B 抛出的错误

Why can't function A catch the error thrown by function B

javascript

try-catch-finally