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JavaScript Object Spread — exercises and bug fixes

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

    Copy an object

    easy10 min

    Copy an object, change the copy, and show the original is untouched.

  2. 2

    Merge two objects

    easy10 min

    Merge defaults with user settings so the user value wins.

  3. 3

    Update one property

    easy10 min

    Build a new object with active set to true, leaving the original alone.

  4. 4

    Collect the rest

    easy10 min

    Pull out the id and collect the remaining properties, then list their names.

  5. 5

    Add a property while copying

    medium10 min

    Copy an object and add a year in the same expression.

Find the bug(5)

  1. 1

    Fix the shared object

    easy8 min

    Assigning does not copy, so both names point at the same object.

  2. 2

    Fix the merge order

    easy8 min

    The defaults are overwriting the user's choice.

  3. 3

    Fix the original being changed

    easy8 min

    The update should build a new object rather than editing the old one.

  4. 4

    Fix the rest that took everything

    easy8 min

    The id should be pulled out before the rest is collected.

  5. 5

    Fix the property added after the spread

    easy8 min

    The added property is being overwritten by the spread that follows it.

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