Async /await not working on making a fetch API call in javascript

Question

I am making a fetch API call from my js file ,I have a doubt that when i am using Async/await still the code is executing in asynchronous manner.

I have also tried await at differnt place but its doesn't work.

 let info
 async function weather(){
 // API call
 let data=await fetch('http://api.openweathermap.org/data/2.5/weather?'+'&lat=20&lon=44'+'&units=metric'+'&APPID='+WEATHER_KEY)
  console.log("inside API")
  const res= await data.json();
  console.log(res)
 }
weather()
console.log("last part")

OUTPUT:

last part

inside API

"VALUE OF RES"

WHAT I EXPECT:

inside API

"VALUE OF RES"

last part

Any help will be highly appreciated..

JavaScript is asynchronous, the "last part" runs first because the await hasn't returned a result yet. — doublesharp
– doublesharp, Commented Jan 3, 2019 at 15:50
And to await weather() the whole things needs to be inside another async function. — doublesharp
– doublesharp, Commented Jan 3, 2019 at 15:51
As you wrote it yourself, weather() is asynchronous. Meaning non-blocking, meaning console.log("last part") won't wait for it to complete. — Jeremy Thille
– Jeremy Thille, Commented Jan 3, 2019 at 15:52

doublesharp · Accepted Answer · 2019-01-03 16:08:31Z

1

The easiest way is to wrap it all in another async function so that you can await weather().

// this function fetches the weather then logs the result
async function weather() {
  // API call
  let data = await fetch('http://api.openweathermap.org/data/2.5/weather?'+'&lat=20&lon=44'+'&units=metric'+'&APPID='+WEATHER_KEY);
  console.log('inside API');
  const res = await data.json();
  console.log(res);
}

// this async function awaits for weather() to return
async function run() {
  await weather();
  console.log('last part');
}

// this runs first
run();

edited Jan 3, 2019 at 16:08

answered Jan 3, 2019 at 15:54

doublesharp

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Comments

vinoth s · Accepted Answer · 2019-01-03 15:53:39Z

0

// async function
async function fetchAsync () {
  // await response of fetch call
  let response = await fetch('http://api.openweathermap.org/data/2.5/weather?'+'&lat=20&lon=44'+'&units=metric'+'&APPID='+WEATHER_KEY);
  // only proceed once promise is resolved
  let data = await response.json();
  // only proceed once second promise is resolved
  return data;
}

// trigger async function
// log response or catch error of fetch promise
fetchAsync()
    .then(data => console.log(data))
    .catch(err => console.log(err))

answered Jan 3, 2019 at 15:53

vinoth s

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Comments

Juan Carlos Serrano · Accepted Answer · 2019-04-20 17:49:58Z

0

A solution in a script that run in node environment:

(async function () {

  // API call
  const data = await fetch('http://api.openweathermap.org/data/2.5/weather?'+'&lat=20&lon=44'+'&units=metric'+'&APPID='+WEATHER_KEY)
  console.log("inside API")

  const res = await data.json();
  console.log(res)

  console.log("last part")
})()

The messages will are in expected order.

answered Apr 20, 2019 at 17:49

Juan Carlos Serrano

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