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JavaScript Classes — exercises and bug fixes

5 hands-on exercises and 5 find-the-bug challenges for the JavaScript Classes 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

    Write a class

    easy10 min

    Create a Person class with a name and report it.

  2. 2

    Build two instances

    easy10 min

    Create two cars with different brands and report both.

  3. 3

    Add a method

    easy10 min

    Give the class a greet method and call it.

  4. 4

    Show a class is a function

    easy10 min

    Report the typeof a class.

  5. 5

    Store two properties

    medium10 min

    Store a name and a role, then report them together.

Find the bug(5)

  1. 1

    Fix the missing new

    easy8 min

    A class must be called with new.

  2. 2

    Fix the comma between methods

    easy8 min

    Class methods are not separated by commas.

  3. 3

    Fix the property never stored

    easy8 min

    The constructor takes a name but never puts it on the instance.

  4. 4

    Fix the shared instance

    easy8 min

    One object is being reused, so both cars have the same brand.

  5. 5

    Fix the method missing this

    easy8 min

    Without this the method cannot see the instance property.

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