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JavaScript Errors — exercises and bug fixes

5 hands-on exercises and 5 find-the-bug challenges for the JavaScript Errors lesson. Every one is checked automatically in the browser — write the code, run it, and the tests tell you what still fails.

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Exercises(5)

  1. 1

    Catch a failure

    easy10 min

    Catch the error and report a message.

  2. 2

    Carry on afterwards

    easy10 min

    Show that the program continues after a caught error.

  3. 3

    Read the error name

    easy10 min

    Report the name of the error that was thrown.

  4. 4

    Read the error message

    easy10 min

    Report the message of an error you throw yourself.

  5. 5

    Let an error travel up

    medium10 min

    Catch at the top an error thrown two functions down.

Find the bug(5)

  1. 1

    Fix the missing try block

    easy8 min

    Without a try the error stops everything after it.

  2. 2

    Fix the message read as a name

    easy8 min

    The name is the type; the message is the description.

  3. 3

    Fix the logic error treated as catchable

    easy8 min

    Wrong brackets do not throw, so try cannot help.

  4. 4

    Fix the catch placed too deep

    easy8 min

    The inner function swallows an error the caller needed to see.

  5. 5

    Fix the code placed after the failure

    easy8 min

    Statements after the throwing line inside try never run.

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