Explain the use of the componentDidCatch method.

componentDidCatch(error, info) This lifecycle method is invoked after an error has been thrown by a descendant component.

It receives two parameters:

1
error - The error that was thrown.
2
info - An object with a componentStack key containing information about which component threw the error.

1
componentDidCatch() is called during the “commit” phase, so side-effects are permitted.
2
It should be used for things like logging errors:

Difficulty: 5/10

Topics: error boundaries, fallback UI, error logging

0-2 years experience

1
How would you add an error boundary around a component that fetches data, and what would you show to the user when an error occurs?
2
What happens to the UI if a child component throws an error and you haven't implemented componentDidCatch?

2-5 years experience

1
We have a third‑party chart library that sometimes throws during render. How would you use componentDidCatch to keep the page alive, and what trade‑offs would you consider for the fallback UI?
2
During debugging you notice errors in a lazy‑loaded route aren't being caught. Why might componentDidCatch not fire there, and how would you fix it?

5-8 years experience

1
In a large app with many nested error boundaries, how would you design a strategy to log errors from componentDidCatch to a central monitoring service without hurting performance?
2
If a componentDidCatch boundary catches an error but the layout still looks broken, how would you diagnose and resolve the issue considering React's reconciliation process?

8+ years experience

1
Our legacy codebase mixes class components with functional components using hooks. How would you plan a migration to a unified error‑handling approach that leverages componentDidCatch or its hook equivalents while keeping backward compatibility?
2
When introducing a global error boundary across micro‑frontends, what architectural considerations arise regarding user experience, error reporting, and isolation of failures?

❓What are the main limitations of componentDidCatch?
❓How would you test that your error boundary works as expected?
❓Can you describe how you would send the caught error to an external monitoring service?