CODEWITHSUNDEEP
javascriptnode.jspromise
Sharjeel Malik
Sharjeel Malik

Reputation: 23

Returning Promise says Promise Pending, Node js?

I am new to Nodejs and first time working on promises so now the context is when I try to return promise it shows status Promise . How to fix it can anyone guide me through this?

Here is the code where I am calling a function that will return a promise. bold line showing where I want to return that promise and store in an object.

for(let i = 0; i<responseArray.length; i++){
                    let dollar = {
                            amount : 0
                    };
                    if(i == 1){
                        continue;    
                    }                   
                   dollar.amount = **currenciesService.getCurrencyLatestInfo(responseArray[i].currency);**
                   dollarAmount.push(dollar);
                }
                console.log("$", dollarAmount);

Here is a code which is returning promise.

const getCurrencyLatestInfo = function(currency) {
return new Promise(function(resolve, reject) {
    request('https://min-api.cryptocompare.com/data/price?fsym='+currency+'&tsyms='+currency+',USD', { json: true }, (err, res, body) => 
    {
        if (err) {
            reject(err);
        } else {
            var result= body;
            resolve(result);
            console.log("RESULT: ",result.USD); 
        }
    });
})

}

Upvotes: 0

Views: 4206

Answers (1)

Jaromanda X
Jaromanda X

Reputation: 1

You'll need to wait for those promises to resolve before you can use the resolved values

here is a small rewrite of your loop that should work

let promises = [];
for(let i = 0; i<responseArray.length; i++){
    if(i == 1){
        continue;    
    }                   
   let dollar = currenciesService.getCurrencyLatestInfo(responseArray[i].currency)
       .then(amount => ({amount})); // do you really want this?
   promises.push(dollar);
}
Promise.all(promises)
.then(dollarAmount =>console.log("$", dollarAmount))
.catch(err => console.error(err));

This should result in an array like [{amount:123},{amount:234}] as your code seems to expect

The above can also be simplified to

Promise.all(
    responseArray
    .filter((_, index) => index != 1)
    .map(({currency}) => 
        currenciesService.getCurrencyLatestInfo(currency)
        .then(amount => ({amount})) // do you really want this?
    )
)
.then(dollarAmount =>console.log("$", dollarAmount))
.catch(err => console.error(err));

Note: your original code suggests you want the results to be in the form {amount:12345} - which seems odd when you want to console.log("$", ....) ... because the console output would be something like

$ [ { amount: 1 }, { amount: 0.7782 } ]

given two results of course - can't see your responseArray so, am only guessing

Upvotes: 1

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