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Intermediate

12h

Updated 5 months ago

JavaScript Promises
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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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Overview

Content

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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.

Promises are used to deal with event handling and callbacks in asynchronous programming in JavaScript, such as clicks and key pr...Show More

WHAT YOU'LL LEARN

An in-depth understanding of JavaScript promises

An understanding of the asynchronous programming in JavaScript

Hands-on experience creating settled and unsettled promises

A working knowledge of chaining promises

Familiarity with monitoring and responding to promises executing in parallel

The ability to track unhandled rejections

An in-depth understanding of JavaScript promises

Content

40 Lessons5 Quizzes

Introduction

2 Lessons

Get familiar with JavaScript promises, enhancing asynchronous programming and improving code clarity.

What’s This Course About?

Introduction to JavaScript Promises

Basics of Promises

8 Lessons

Unpack the core of JavaScript promises, their states, handlers, and construction methods.

Fundamentals of Promises

Handlers

Handlers Executed as Microtasks

Unsettled Promises

Settled Promises

Non-Promise Thenables

Summary: Basics of Promises

Quiz: Basics of Promises

Chaining Promises

7 Lessons

Examine JavaScript promise chaining to handle sequential async operations and centralized error management.

Fundamentals of Chaining Promises

Promise Chains with the finally() Method

Return Values in Promise Chains

Return Promises in Promise Chains

Return Promises from finally()

Summary: Chaining Promises

Quiz: Chaining Promises

Working with Multiple Promises

10 Lessons

Grasp the fundamentals of managing multiple promises using Promise.all(), allSettled(), any(), and race().

The Promise.all() Method

When to Use the Promise.all() Method

The Promise.allSettled() Method

When to Use the Promise.allSettled() Method

The Promise.any() Method

When to Use the Promise.any() method

The Promise.race() Method

When to Use Promise.race()

Summary: Working with Multiple Promises

Quiz: Working with Multiple Promises

Async Functions and Await Expressions

7 Lessons

Take a closer look at async functions, await expressions, and promise handling in JavaScript.

Async Functions

What Makes Async Functions Different?

Await Expressions

Await Expressions and Promises

Await Expressions and Loops

Summary: Async Functions and Await Expressions

Quiz: Async Functions and Await Expressions

Tracking Down the Unhandled Rejections

5 Lessons

Focus on tracking and managing unhandled promise rejections across JavaScript environments.

How to Detect an Unhandled Rejection

Web Browsers and Unhandled Rejections

Detecting Unhandled Rejections with Node.js

Summary: Tracking Down the Unhandled Rejections

Quiz: Tracking Down the Unhandled Rejections

Conclusion

1 Lessons

Build on key concepts of JavaScript promises, async/await, and error handling.

Final Remarks

Certificate of Completion

Showcase your accomplishment by sharing your certificate of completion.

Course Author:

Nicholas Zakas

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