flexpath-intro-to-async-and-error-handling-exercises

Exercise overview

The intention of this exercise is to introduce you to asynchronous operations in JavaScript.

Getting Started

1. Using Visual Studio Code, open the folder flexpath-intro-to-async-and-error-handling-exercises wherever you saved it on your device.
2. Your VS code file explorer window should look like this:
3. Then open up the exercises.js file in the flexpath-intro-to-async-and-error-handling-exercises folder. Inside of this file we have provided exercises for you to complete, written in code comments. For each exercise, please code ONLY in the space between the comments // CODE IN THE OPEN LINES BELOW and // CODE IN THE OPEN LINES ABOVE
4. To run your code for different exercises, you will update the exercise mentioned on line 25 of the file.
5. After changing that line, make sure to SAVE the file before running it.
6. To run your code in exercises.js, you will update line 25 to run the exercise code you want to run and save the file. THEN, open a Terminal window in VS Code by going to your toolbar at the top of the page and selecting "Terminal" -> "New Terminal"
7. Inside of this terminal, check that you have Node.js installed by running the command node -v. If your computer doesn't recognize that keyword, please go back and ensure you installed Node.js correctly.
8. To run exercises.js you will then use the command node exercises.js in the terminal to run the file.

We have included the screen recording from exercise 2 showing how to run these types of exercise files.

VIDEO DISCLAIMER - You will need to clone the repo to your local device before you can watch the .mp4 file since GitHub does not support watching it from here.

Exercise solutions are in the /solution folder

 

Summary of JavaScript Concepts Covered in These Exercises

1. Asynchronous Programming:

   • Explanation of synchronous vs. asynchronous operations.
   • Use cases for asynchronous logic, such as API calls and file operations.
   • Working with callbacks, promises, and async/await.
   • Understanding callback hell and the pyramid of doom.

2. Callbacks:

   • Writing functions that are executed after an asynchronous task completes.
   • Handling errors in callbacks and passing results as parameters.

3. Promises:

   • Creating and using promises to manage asynchronous operations.
   • Chaining promises to handle sequential asynchronous tasks.
   • Using .then(), .catch(), and .finally() for promise handling.
   • Error handling in promise chains.

4. Async/Await:

   • Simplifying asynchronous code using async/await syntax.
   • Using try-catch blocks for error handling in async/await.
   • Understanding top-level await in modern JavaScript.

5. Error Handling:

   • Using try-catch for both synchronous and asynchronous code.
   • Throwing custom errors and handling them in a structured way.

6. Node.js File System API:

   • Using the callback and promise-based versions of the Node.js File System API.
   • Reading and writing files asynchronously with proper error handling.

7. Event Handling:

   • Using the EventEmitter in Node.js to listen for and emit events.
   • Examples of handling system events, mouse clicks, and keypresses.

8. Global Promise Methods:

   • Using Promise.all, Promise.allSettled, Promise.any, and Promise.race for managing multiple promises concurrently.