await can only be used in async wrapped functions.
Just like yield, it can only be used in the generator function.

Didn’t I say it above? Throw it into the async function.

var sleep = async function(para) { return new Promise(function(resolve, reject) { setTimeout(function() { resolve(para * para) }, 1000) }) } var errorSleep =async function(para) { return new Promise(function(resolve, reject) { setTimeout(function() { reject(' ErrorSleep') }, 1000) }) } //一样丢到async函数里 var af = async function() { try { var result1 = await sleep(1); var result2 = await errorSleep(4); var result3 = await sleep(1); console.log('result1: ', result1) console.log('result2: ', result2) console.log('result3: ', result3) } catch (err) { console.log('err: ', err) console.log('result1: ', result1) console.log('result2: ', result2) console.log('result3: ', result3) } } af();

awaitcan only be used inasyncfunctions (functions, function expressions, arrow functions), so you only need to write anasyncfunction to wrap that code. I prefer to writemainfunction instead of running directly in the global scope

async function main() { try { var result1 = await sleep(1); var result2 = await errorSleep(4); var result3 = await sleep(1); console.log("result1: ", result1); console.log("result2: ", result2); console.log("result3: ", result3); } catch (err) { console.log("err: ", err); console.log("result1: ", result1); console.log("result2: ", result2); console.log("result3: ", result3); } } // 记得调用 main();

In addition, you can also useasyncIIFE expression, such as

// IIFE 函数表达式 (async function() { // todo main process })(); // IIFE Lambda 表达式(箭头函数表达式) (async () => { // todo main process })();