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JavaScript Function Declarations — exercises and bug fixes

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

    Declare a function

    easy10 min

    Declare a function named square and show square of 9.

  2. 2

    Call before the declaration

    easy10 min

    Call a declared function on a line above it and show the answer for 7.

  3. 3

    Two parameters

    easy10 min

    Declare a function that joins a first and last name with a space.

  4. 4

    No parameters

    easy10 min

    Declare a function that takes nothing and returns the word Ready.

  5. 5

    Branch inside a function

    medium10 min

    Declare a function returning Adult for 18 or over, Minor otherwise. Show the answer for 15.

Find the bug(5)

  1. 1

    Fix the misspelled keyword

    easy8 min

    The keyword is function, spelled in full.

  2. 2

    Fix the duplicate declaration

    easy8 min

    The later declaration replaces the first one.

  3. 3

    Fix the swapped parameters

    easy8 min

    The names come back in the wrong order.

  4. 4

    Fix the missing space

    easy8 min

    The two names run together with no gap.

  5. 5

    Fix the inverted condition

    easy8 min

    The age test is the wrong way round.

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