Declare a function — practice exercise

What you'll be asked to do

1. 1.Declare a functionexercise · easy · 10 min

   Declare a function named square and show square of 9.

   Passes when: #out should show 81.

2. 2.Call before the declarationexercise · easy · 10 min · practice plan

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

   Passes when: #out should show 49.

3. 3.Two parametersexercise · easy · 10 min · practice plan

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

   Passes when: #out should show Ada Lovelace.

4. 4.No parametersexercise · easy · 10 min · practice plan

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

   Passes when: #out should show Ready.

5. 5.Branch inside a functionexercise · medium · 10 min · practice plan

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

   Passes when: #out should show Minor.

6. 6.Fix the misspelled keywordbug fix · easy · 8 min

   The keyword is function, spelled in full.

   Passes when: #out should show 81.

7. 7.Fix the duplicate declarationbug fix · easy · 8 min · practice plan

   The later declaration replaces the first one.

   Passes when: #out should show Second wins.

8. 8.Fix the swapped parametersbug fix · easy · 8 min · practice plan

   The names come back in the wrong order.

   Passes when: #out should show Ada Lovelace.

9. 9.Fix the missing spacebug fix · easy · 8 min · practice plan

   The two names run together with no gap.

   Passes when: #out should show Ada Lovelace with a space.

10. 10.Fix the inverted conditionbug fix · easy · 8 min · practice plan

    The age test is the wrong way round.

    Passes when: #out should show Minor for age 15.

Between them these tasks cover Function declarations, Hoisting and Naming.

Looking for a different chapter? See every practice set, or switch to the interview theory questions.