Catch a rejection — practice exercise

What you'll be asked to do

1. 1.Catch a rejectionexercise · easy · 10 min

   Catch a rejected promise and report the message.

   Passes when: #out should show caught: no network.

2. 2.Catch a thrown errorexercise · easy · 10 min · practice plan

   Throw inside a then and catch it.

   Passes when: #out should show something broke.

3. 3.Clean up with finallyexercise · easy · 10 min · practice plan

   Handle a rejection then report that cleanup ran.

   Passes when: #out should show handled and cleaned.

4. 4.Check the error typeexercise · easy · 10 min · practice plan

   Report whether the rejection reason is an Error object.

   Passes when: #out should show true.

5. 5.Recover from a failureexercise · medium · 10 min · practice plan

   Catch a rejection and continue the chain with a fallback value.

   Passes when: #out should show used the fallback.

6. 6.Fix the missing catchbug fix · easy · 8 min

   The rejection is never handled, so nothing is reported.

   Passes when: #out should show handled: gone.

7. 7.Fix the message read from a stringbug fix · easy · 8 min · practice plan

   A rejection reason that is a plain string has no message property.

   Passes when: #out should show caught: no network.

8. 8.Fix finally expected to receive a valuebug fix · easy · 8 min · practice plan

   finally gets no argument; the value passes straight through.

   Passes when: #out should show value is here.

9. 9.Fix the throw outside the chainbug fix · easy · 8 min · practice plan

   A throw outside a promise handler is not caught by catch.

   Passes when: #out should show caught: broke.

10. 10.Fix the chain that stops at the catchbug fix · easy · 8 min · practice plan

    The catch should return a value so the next step can use it.

    Passes when: #out should show used the fallback.

Between them these tasks cover catch, finally and Error objects.

Looking for a different chapter? See every practice set, or switch to the interview theory questions.