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Are there still reasons to use Promise libraries?
For example if you are starting a new project and let’s assume in this project you don’t have any dependencies that use these libraries, can we say that there are really no more reasons to use such libraries? native promises have very very basic features. If you need those features then use those libraries.
What does a promise return?
Returns a new Promise object that is resolved with the given value. If the value is a thenable (i.e. has a then method), the returned promise will “follow” that thenable, adopting its eventual state; otherwise, the returned promise will be fulfilled with the value.
Are promises provided by libraries?
Some libraries were written for the sole purpose of providing promises while established libraries like jQuery added them to handle their async APIs. Promise libraries can act as polyfills in older web browsers and other environments where native promises are not provided.
What do you mean by promise in ES6?
A Promise is an object that is used as a placeholder for the eventual results of a deferred (and possibly asynchronous) computation. Simply, a promise is a container for a future value. If you think for a moment, this is exactly how you use the word promise in your normal day-to-day conversation.
Is there a need for promises in JavaScript?
For asynchronous programming, JavaScript used callbacks but there is a problem using the callback which is callback hell or Pyramid of Doom. Using the ES6 Promise will simply avoid all the problems associated with the callback. Need of Promises: The Callbacks are great when dealing with basic cases.
Are there still reasons to use promise libraries like Q?
If you’re also using jQuery, you can sometimes just use the promise support built into jQuery (though it is painfully non-standard in some ways, perhaps fixed in jQuery 3.0), but if the project involves any signficant async activity, I find the extended features in Bluebird very useful.
How are promises used in JavaScript async programming?
Promises are a way to implement async programming in JavaScript (ES6). A Promise will become a container for future value. Like if you order any food on any site to deliver it to your place that order record will be the promise and the food will be the value of that promise. So the order details are the container of the food you ordered.