Deno just released v1.0.
When I was checking getting started guild I show some unusual code.
import { serve } from "https://deno.land/[email protected]/http/server.ts";
const s = serve({ port: 8000 });
console.log("http://localhost:8000/");
for await (const req of s) {
req.respond({ body: "Hello World\n" });
}
If you see for loop there is await without async.
So I'm wondering, is javascript async/await and deno await both are same or it's different?
Deno supports top-level await which is currently on stage 3.
Top-level await enables modules to act as big async functions: With top-level await, ECMAScript Modules (ESM) can await resources, causing other modules who import them to wait before they start evaluating their body.
top-level await allows you to initialize a module with asynchronously fetched data.
// my-module.js
const res = await fetch('https://example.com/some-data');
export default await res.json();
// some module
import data from './my-module.js';
console.log(data); // { "some": "json" }
If you see for loop there is await without async.
Have in mind that functions using await will still need async keyword, even if top-level await is supported.
function foo() { // async is needed
const res = await fetch('https://example.com/api/json')
console.log(res);
}
foo();
The above snippet still throws an error.
References:
Deno implements top-level await.
Top-level await enables developers to use the await keyword outside of async functions. It acts like a big async function causing other modules who import them to wait before they start evaluating their body.
