Gain insights into JavaScript Promises to handle asynchronous events, chain multiple promises, utilize built-in methods, and master async functions with await expressions for efficient event handling.



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JS promises

promises

Promises are used to deal with event handling and callbacks in asynchronous programming in JavaScript, such as clicks and key presses. Promises allow developers to specify a function to execute at some later point in response to certain events. Promises may also indicate whether a certain code succeeded or failed in performing its assigned job.

In this course, you will learn how to chain different promises, which makes the code easier to understand and debug. Next, you’ll learn built-in methods to monitor and respond to multiple promises executing in parallel. Then, you will cover async functions and await expressions that are often used with promises. Finally, you’ll learn how to track promises when they are rejected without a rejection handler.

Promises are important to understand and debug the code in asynchronous programming. The concepts of JS promises help developers working with Node.js and Deno for event handling and with asynchronous JavaScript APIs.

JavaScript Promises

The `Promise.any()` method is best used in situations where we want any one of the promises to `fulfill`, regardless of how many others `reject`, unless they all `reject`. Here are some situations where we might want to use `Promise.any()`.

## Executing hedged requests
A **hedged request** is one where the client makes requests to multiple servers and accepts the response from the first that replies. This is helpful in situations where the client needs the lowest latency possible and there are server resources devoted to managing the extra load and deduplicating responses. Here’s an example:

The `Promise.any()` method is best used in situations where we want any one of the promises to `fulfill`, regardless of how many others `reject`, unless they all `reject`. Here are some situations where we might want to use `Promise.any()`.

# Executing hedged requests
A **hedged request** is one where the client makes requests to multiple servers and accepts the response from the first that replies. This is helpful in situations where the client needs the lowest latency possible and there are server resources devoted to managing the extra load and deduplicating responses. Here’s an example:

Discover how Promise.any() executes hedge requests, and choose the fastest service.

Introduction

Basics of Promises

Chaining Promises

Working with Multiple Promises

Async Functions and Await Expressions

Tracking Down the Unhandled Rejections

Conclusion

When to Use the Promise.any() method

Executing hedged requests