JuniorTheoryCommon

What does the program print (lines separated by spaces)?

JavaScript

async function load() {
    throw new Error("bad");
}

try {
    load().catch(() => console.log(1));
    console.log(2);
} catch (e) {
    console.log(3);
}

2 1

Expecting 3: a throw inside an async function does not throw at the call; it rejects the returned promise, so only .catch sees it.
Expecting 1 first: the .catch callback waits in the microtask queue until the current code, including console.log(2), has finished.

How do you change the program so that the try…catch block catches the error?
What happens if you remove .catch(() => console.log(1))?

Back to questions Open topic in roadmap →Answer it yourself — Quiz

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JuniorTheoryCommon

What does the program print (lines separated by spaces)?

JavaScript

async function load() {
    throw new Error("bad");
}

try {
    load().catch(() => console.log(1));
    console.log(2);
} catch (e) {
    console.log(3);
}

2 1

Expecting 3: a throw inside an async function does not throw at the call; it rejects the returned promise, so only .catch sees it.
Expecting 1 first: the .catch callback waits in the microtask queue until the current code, including console.log(2), has finished.

How do you change the program so that the try…catch block catches the error?
What happens if you remove .catch(() => console.log(1))?

Back to questions Open topic in roadmap →Answer it yourself — Quiz