Catching Errors in JavaScript Promises with a First Level try … catch

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You cannot use try-catch statements to handle exceptions thrown asynchronously, as the function has “returned” before any exception is thrown. You should instead use the promise.then and promise.catch methods, which represent the asynchronous equivalent of the try-catch statement. (Or use the async/await syntax noted in @Edo’s answer.)

What you need to do is to return the promise, then chain another .catch to it:

function promise() {
    var promise = new Promise(function(resolve, reject) {
        throw('Oh no!');
    });

    return promise.catch(function(error) {
        throw(error);
    });
}

promise().catch(function(error) {
    console.log('Caught!', error);
});

Promises are chainable, so if a promise rethrows an error, it will be delegated down to the next .catch.

By the way, you don’t need to use parentheses around throw statements (throw a is the same as throw(a)).

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