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How To Create a Promise in JavaScript?
The developers from the leading AngularJS development company implements Promises by calling the then() and catch() methods.
● then() method: It takes two callback functions as parameters and is invoked when a promise is either resolved or rejected.
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● catch() method: It takes one callback function and is invoked when an error occurs.
What is Promise inAngular?
When working with asynchronous actions like an HTTP request, AngularJS developers are sceptical of when they will receive a response from the server. By default, Javascript is a programming language that is Synchronous; Blocking; and Single-threaded language.
Simply put, we may state that only one code can be processed by the Javascript engine at a time in a single thread. Hence, when a thread is blocked, we are unable to execute other blocked code, which slows down JS and prevents it from performing multiple actions.
On the other hand, code becoming non blocking is entirely the result of the asynchronous activity. That means that it enables developers to run many pieces of code simultaneously.
In theAngular framework, the developers can quickly achieve asynchronous by utilising the following method.
● The Callback function
● The Promise from Javascript can be used inAngular.
● Observable using Rxjs library inAngular: Library for reactive programming using Observables. Additionally, developers can swiftly shift the code to the following line by allowing the user interface to stay responsive while dealing with an asynchronous activity. As HTTP requests and other asynchronous actions are carried out in the background, the user keeps working on the application. Now Angular's Promise notion enters the scene. Javascript's promise is just a task wrapped in an asynchronous operation that receives notifications whenever it is successful or unsuccessful in the future.
As the developer executes the Promise, one of two things can happen: the Promise is successful or fails. Developers may deal with easy-to-read and write code using the async and await keywords with Promise, and we can also utilise "try and catch" for error management (async & await).
