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re: JavaScript: Error handling with Promises and Async/Await VIEW POST

FULL DISCUSSION
 

Very useful, thank you :) I was just a bit confused by this statement, it seems to contradict itself?:

"But the problem with the above module is that when we throw a new Error inside the then block of the promise, it will always pass to the catch block of the promise. That is because throwing a new error inside a then block of a promise will always be passed to the catch block of the invoking promise function."

 

@fluffystark pretty much answers your question. However, I'll explain it further just in case -

Say you have a promise function called somePromise. When you do a throw new Error() inside your .then() block, like below

try {
    somePromise()
        .then((data) => {
            throw new Error('Inner error');
        })
        .catch((promiseError) => {
            console.log(promiseError); // Prints Inner error
        });
} catch (error) {
    // Handle all module errors here
}

the error will get passed to the .catch() block of somePromise() and not the catch block of the try-catch.

When having multiple promise statements in your code, it can become cumbersome to handle each promise's errors in its own .catch() block. Using async/await allows you to handle all errors in one place. I hope this cleared your doubt. :)

 

I think the catch block it was referring to is the catch block right after the then block. But the goal was to have a single catch block do all the error handling but from that code, it had two catch blocks ( 1. for module errors, 2. for promise/then errors )

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