Q1. Why do you need a promise?
Promises are **used to handle asynchronous operations**, especially in languages like JavaScript, which often work with non-blocking operations such as network requests, ...
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Q2. Explain the three states of promise?
Promises have three states: 1. **Pending:** This is an initial state of the Promise before an operation begins 2. **Fulfilled:** This state indicates that the specified o...
Q3. What is promise chaining?
The process of executing a sequence of asynchronous tasks one after another using promises is known as Promise chaining. Let's take an example of promise chaining for cal...
Q4. What is promise.all?
`Promise.all()` is a built-in JavaScript method used to handle multiple asynchronous operations together. It accepts an iterable of promises (usually an array) and return...
Q5. Does Promise.all() cancel the other Promises?
No. `Promise.all()` does not cancel the other promises. It only waits for all of them to finish, and if any one rejects, the overall `Promise.all()` call rejects immediat...
Q6. What are the pros and cons of promises over callbacks?
Below are the list of pros and cons of promises over callbacks, **Pros:** 1. It avoids callback hell which is unreadable 2. Easy to write sequential asynchronous code wit...
Q7. What are dynamic imports?
The dynamic imports using `import()` function syntax allows us to load modules on demand by using promises or the async/await syntax. Currently this feature is in [stage4...
Q8. What are the different ways to deal with Asynchronous Code?
Below are the list of different ways to deal with Asynchronous code. 1. Callbacks 2. Promises 3. Async/await 4. Third-party libraries such as async.js,bluebird etc
Q9. How to cancel a fetch request?
Until a few days back, One shortcoming of native promises is no direct way to cancel a fetch request. But the new `AbortController` from js specification allows you to us...
Q10. What are the differences between promises and observables?
Some of the major difference in a tabular form | Promises | Observables | | ------------------------------------------------------------------ | -------------------------...