Node.js 如何使用Async-Await模式的示例
现代JavaScript带来了async-await功能,使开发人员能够以看起来和感觉像同步的方式编写异步代码。这有助于消除promise嵌套带来的许多问题,并且作为一个额外的好处,可以使异步代码更容易阅读和编写。
要使用async-await,我们只需要创建一个async函数,在其中实现我们的try-catch块。在try块中,我们将等待我们的promise完成。如果它被解决,我们将获得结果,否则将通过catch块抛出错误。等待只能在async函数、async回调或async箭头函数中使用。
示例:
<script>
function makeConnection(request) {
// Promise resolves if connection is
// made to GFG else it is rejected
return new Promise((resolve, reject) => {
if (request == 'GFG')
resolve('Connected :)');
else reject('Connection failed :(');
});
}
async function doStuff(request) {
try {
const response = await makeConnection(request);
console.log(response);
} catch (err) {
console.log(err);
}
}
// Makes connection request to GFG
doStuff('GFG');
// Makes connection request to Google
doStuff('Google');
</script>
输出:
Connected :)
Connection failed :(