How to work with error handling in Javascript

In programming unintended side-effects called errors can and will happen in your code. Allowing these errors to be introduced to people that are using your programs is frowned upon and a very bad user experience.

Error Handling is the technique of smoothly handling these errors and providing useful information to a user.

Here are the important parts of error handling:

Try

The try block allows you to try an initial blog of code.

async function doWork() {  try {    let response = await fetch("www.worktobedone.com")     let work = await response.json()    return work  }}

Catch

The catch block allows you to catch an error from the initial blog of code.

async function doWork() {  try {    let response = await fetch("www.worktobedone.com")     let work = await response.json()    return work  } catch(error) {     // Here we caught an error to alert     alert(error)  }}

Throw

The throw keyword allows you to control or create custom exceptions from your code.

async function doWork() {  try {    let response = await fetch("www.worktobedone.com")     let work = await response.json()    return work  } catch(error) {     // Lets change the error output     throw new Error(`Oops we found this error during work - ${error}`)  }}

Finally

The finally block allows you to execute code regardless of errors in the try and catch blocks.

async function doWork() {  try {    let response = await fetch("www.worktobedone.com")     let work = await response.json()    return work  } catch(error) {     throw new Error(`Oops we found this error during work - ${error}`)  } finally {   return "My work here is done."  }}

Let's chat about error handling

This walkthrough showed the steps to using the try..catch...finally block to handle errors. If you enjoyed this post feel free to leave a comment about your thoughts and experiences handling errors in your code.

Happy Coding,
Terry Threatt