Observable vs Promise in Angular
Choosing Between Observables and Promises in Angular
Observable vs Promise in Angular
In Angular, observables and promises are both used for handling asynchronous operations, but they have key differences. Observables are streams of data that can emit multiple values over time, allowing for more powerful operations like mapping, filtering, and combining. They are also cancellable and can handle multiple event listeners. On the other hand, promises represent a single value that will be delivered at a future point in time, and once resolved, a promise cannot be cancelled or retried. Observables are preferred in Angular applications due to their flexibility, composability, and built-in support for handling multiple values and events.
To Download Our Brochure: https://www.justacademy.co/download-brochure-for-free
Message us for more information: +91 9987184296
1 - Observables and Promises are both used in Angular to handle asynchronous operations, but they have some key differences.
2) Observables are used for handling streams of data over time, allowing for multiple values to be emitted over a period of time.
3) Promises, on the other hand, are used for handling a single asynchronous operation that will either succeed or fail, with a single value being returned.
4) Observables offer more powerful features such as the ability to cancel a subscription, retrying, and transforming data streams using operators.
5) Promises are simpler to use and understand, as they represent the result of an asynchronous operation at a specific point in time.
6) Observables are lazy and do not execute until they are subscribed to, while Promises are eager and start executing as soon as they are created.
7) Observables can handle multiple values over time, making them more suitable for scenarios like real time data updates or event streams.
8) Promises are more suited for scenarios where you only expect a single result, such as fetching data from an API endpoint.
9) Promises can only handle success or failure, while Observables can handle multiple types of notifications including error, completion, and data values.
10) Observables can be transformed and combined with other Observables using operators like map, filter, combineLatest, and mergeMap.
11) Promises do not have built in operators for transforming or combining, making them less flexible compared to Observables.
12) Observables are cancellable, meaning you can unsubscribe from them to stop receiving further data updates.
13) Promises do not have a built in mechanism for cancellation, once created they will resolve or reject based on the async operation's completion.
14) Observables are commonly used with Angular's HttpClient for making HTTP requests, as it returns Observables for handling the asynchronous nature of network requests.
15) Observables are preferred for handling complex scenarios with multiple asynchronous operations or streams of data, while Promises are preferred for simpler scenarios with a single asynchronous operation.
Browse our course links : https://www.justacademy.co/all-courses
To Join our FREE DEMO Session: Click Here
Contact Us for more info:
- Message us on Whatsapp: +91 9987184296
- Email id: info@justacademy.co
Web Designing Course In Mumbai With Placement
