Can a promise reject after resolving?
Although we can’t change a settled promise state, rejecting or resolving won’t stop the execution of the rest of the function. The function may contain code that will create confusing results.
What happens if we call then on a promise that was already resolved before?
4 Answers. As expected: then callback will get called immediately in this case if then was called after promise has already resolved. As others have already pointed out, you can add callbacks with . then before or after the promise has been resolved, and you can even add more than one callback.
Does await wait for Promise?
The await operator is used to wait for a Promise . It can only be used inside an async function within regular JavaScript code; however it can be used on its own with JavaScript modules.
How do I resolve pending promises?
The then method returns a pending promise which can be resolved asynchronously by the return value of a result handler registered in the call to then , or rejected by throwing an error inside the handler called. See the MDN section on Promises. In particular, look at the return type of then().
Why is the getresult function not waiting for a promise?
Inside the getResult () function you may say it must await the result, which makes the execution of getResult () wait for it to resolve the promise, but the caller of getResult () will not wait unless you also tell the caller to ‘await’. And since that is true then why bother to await.
What happens when a function awaits in JavaScript?
So although the line waits, the whole function is still run asynchronously, unless the caller of that function also ‘awaits’… More elaborately explained: When you put async in front of a function, what is actually does is make it return a promise with whatever that function returns inside it.
When does a JavaScript function return a promise?
The function runs asynchronously and when the return statement is executed the promise resolves the returning value. The function “getResult ()” will return a Promise which will resolve once it has finished executing.