returns [object promise] instead of the data

cvem

i fetch some data in getData() and then it gets returned but i cant use the returned data since it becomes an [object promise]. i have tried alot of things but cant get it to work

const test = async (a) => {
       const data= await getData(a)
       console.log(data) // **logs the correct data**
       return data 
}
console.log("asd: "+ test(1)) // **logs [object promise] instead of the data**

Nachfolger

What are you expecting it to return? It's an async function, you need to use the promise that it returns.

const test = async (a) => {
       const data = await getData(a);
       console.log(data);
       return data;
}

test(1).then(d => {
       console.log(d)
});

This code:

const test = async (a) => {
       const data = await getData(a);
       console.log(data);
       return data;
}

Is automatically wrapped in a promise, even if you don't write it.

cvem

Nachfolger

what i want to do is get the String that getData() returns. but for some reason i cant.
instead of getting the string, i get [object Promise]

console.log(getData(1)) // logs [object Promise] but should log the string that getData() returns

this is what getData() returns:

if (aaa.data) {
     let d = aaa.data.results[0]["key"]
     console.log(typeof d) // says its a string
     return d
} else {
     return "false"
}

Sempervivum

Read the article in this link in order to get familiar with async/await:
https://developer.mozilla.org/en-US/docs/Learn/JavaScript/Asynchronous/Async_await

cvem

Thank you guys.

I dont seem to be able to solve my problem tho.

How do i get the returned value out of the promise scope?

axios.get("#").then(res => {
    ....
    ....

    let test = ""
    // getData(1).then(r => console.log(r))
    getData(1).then(r => test = r) // doesnt work
})

Sempervivum

Promises are used mainly when requesting data from the server by a get or post request. In this situation one encounters the following problem: After sending the request it will take some time until the response from the server arrives. Therefore the data provided by the request cannot be returned immediately but a promise is returned instead. As visible in the code nachfolger posted you need to use then in order to get the data instead of the response. The data is available inside then only, therefore you need to do all actions based on the data inside then:

const test = async (a) => {
       const data = await getData(a);
       console.log(data);
       return data;
}

test(1).then(data => {
       console.log(data);
       // perform all actions that access data here
});

BTW: MDN (link I posted above) says about asyns/await:

It makes code much simpler and easier to understand

I do not agree with this statement, IMO the fetch API is more clear and easy to understand.