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JavaScript Array Search — exercises and bug fixes

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

    Find a position

    easy10 min

    Show the index of Banana in a list of fruit.

  2. 2

    Check for a missing value

    easy10 min

    Use includes to check for a fruit that is not in the list.

  3. 3

    Report a missing index

    easy10 min

    Show the value indexOf gives back when nothing matches.

  4. 4

    Find the last match

    easy10 min

    Show the index of the last time a value appears.

  5. 5

    Search from a position

    medium10 min

    Find the next match after index 0 in a list with two matches.

Find the bug(5)

  1. 1

    Fix the truthy index check

    easy8 min

    An index of 0 is falsy, so a match at the front is reported as missing.

  2. 2

    Fix the wrong missing value

    easy8 min

    indexOf returns -1 when nothing matches, not undefined.

  3. 3

    Fix the type mismatch

    easy8 min

    The list holds numbers, but a string is being searched for.

  4. 4

    Fix first used instead of last

    easy8 min

    The last matching position is wanted, not the first.

  5. 5

    Fix the object compared by value

    easy8 min

    Two objects that look alike are still different objects.

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