How can I get data from Promise result?
How can I get data from Promise result?
function getPromise() { return new Promise(function(resolve, reject) { setTimeout(function() { resolve({ ‘country’: ‘INDIA’ }); }, 2000) }) } function getResult() { getPromise() . then(function(response) { return response; }) } let result = getResult(); console. log(result);
How do you use Promise response?
Writing a simple promise The promise constructor takes one argument—a callback with two parameters: resolve and reject. Do something within the callback, perhaps async, then call resolve if everything worked, or otherwise call reject.
How do I return a response from Promise?
What you likely want to do instead is to return the entire promise itself. Then whatever function needs its result can call . then() on the promise, and the result will be there when the promise has been resolved.
How do you access promise objects?
In this case promiseA is resolved with a value – result and then immediately resolves promiseB with the value of result + 1 . Accessing the value of promiseB is done in the same way we accessed the result of promiseA . promiseB. then(function(result) { // here you can use the result of promiseB });
Does promise all maintain order?
One interesting thing about Promise. all is that the order of the promises is maintained. The first promise in the array will get resolved to the first element of the output array, the second promise will be a second element in the output array and so on.
What does promise all return?
The Promise. all() method takes an iterable of promises as an input, and returns a single Promise that resolves to an array of the results of the input promises. This returned promise will resolve when all of the input’s promises have resolved, or if the input iterable contains no promises.
Can I use promise allSettled?
Since ES2020 you can use Promise. allSettled . It returns a promise that always resolves after all of the given promises have either fulfilled or rejected, with an array of objects that each describes the outcome of each promise.
How do you know if Promise is resolved or rejected?
The promise object returned by the new Promise constructor has these internal properties: state — initially “pending” , then changes to either “fulfilled” when resolve is called or “rejected” when reject is called.
What happens if Promise is not resolved?
A promise is just an object with properties in Javascript. There’s no magic to it. So failing to resolve or reject a promise just fails to ever change the state from “pending” to anything else.
Can I use Promise allSettled?
Are promises callbacks?
Promises are not callbacks. A promise represents the future result of an asynchronous operation.
Do promises replace callbacks?
Promise is an object that holds a value that is promised to be given to you at some point in time. One can retrieve the value a Promise is holding by calling the Promises then method. Promises are not callbacks. However, Promises are more than just callbacks.
Does promise all return in same order?
all aggregates all resolved values with an array corresponding to the input order of the original Promises (see Aggregating Promises).
How do you check if all promises are resolved?
Checking if All Promises are Resolved Successfully all() method can be used to check whether all Promises have fulfilled successfully. It accepts an iterable object (e.g. an array) of multiple Promises and returns a Promise. The returned Promise is resolved if all the input Promises passed to it are resolved.
Does promise all keep order?
When would you use promise all () vs promise allSettled ()?
As you might have noticed Promise. allSettled is a method that can be typically used when you have multiple asynchronous tasks that are not dependent on one another to complete successfully, unlike Promise. all() may be more appropriate if the tasks are dependent on each other.