How to save results of a promise to a variable? [duplicate]

问题

I need to fetch some JSON data from an API and assign the result to a variable. I can see the array of data in the console, but [abc] is always set as a Pending promise.

I've tried to assign [abc] instead of logging [data] or simply returning [data] but it's not working. Ideally, I would also want to stop the execution of the following code until I get the required data but with the code I have, the text gets logged before the data

async function fetchData() 
{
  let response = await fetch('API');
  let data = await response.json();
  data = JSON.stringify(data);
  data = JSON.parse(data);
  return data;
}

let abc = await fetchData()
  .then(data => console.log(data)); 

console.log('This should not be logged if 'abc' does not have the data i need')

(data => console.log(data)) ..>> here the data is the array I need but I have no idea on how to assign on a variable.

I've looked for many solutions on the internet but I couldn't find anything that could help.

EDIT 1:

If I assign: let abc = await fetchData() without the then statement it throws me this error: Uncaught SyntaxError: await is only valid in async function

If I then remove the await keyword it returns Promise without having it resolved.

回答1:

In order for await keyword to work, it must sit inside a async function. So you need to wrap your code in a async function first, let's say a main function, then call it. Example:

async function fetchData() {...}

async function main() {
  let abc = await fetchData();
  console.log(abc);
}

main();

回答2:

it should be like this

async function fetchData(){
 let response = await fetch('API');
 let data = await response.json();
 data = JSON.stringify(data);
 data = JSON.parse(data);
 return data;
}

let abc = await fetchData(); // here the data will be return.
console.log(abc); // you are using async await then no need of .then().

来源：https://stackoverflow.com/questions/55595847/how-to-save-results-of-a-promise-to-a-variable

标签

javascript

async-await

es6-promise