What are futures and promises in programming?

Can you explain what futures and promises are in programming?

Sure! Futures and promises are constructs used for asynchronous programming. A promise represents a value that may be available now, or in the future, or never. A future is a placeholder for a result that is initially unknown but will be determined later.

How do they differ from each other?

The main difference is that a promise is a value that you can work with, while a future is a read-only placeholder. You can resolve a promise, but you cannot modify a future once it's created.

Can you give me an example of how to use them?

Certainly! In JavaScript, you can create a promise using the Promise constructor. For example: let myPromise = new Promise((resolve, reject) => { /* async operation */ }); You can then use .then() to handle the resolved value.

Are they used in all programming languages?

Not all languages have built-in support for futures and promises, but many modern languages like JavaScript, Python, and Java do. Each language may implement them differently.