Store a function in a variable — practice exercise

What you'll be asked to do

1. 1.Store a function in a variableexercise · easy · 10 min

   Store a doubling function in a variable and show the result for 16.

   Passes when: #out should show 32.

2. 2.An anonymous functionexercise · easy · 10 min · practice plan

   Store an anonymous function that returns the word Ready.

   Passes when: #out should show Ready.

3. 3.Pass a function to mapexercise · easy · 10 min · practice plan

   Pass a function expression to map to triple each number, then join with commas.

   Passes when: #out should show 3,6,9.

4. 4.A function on an objectexercise · easy · 10 min · practice plan

   Give an object an add method and show 2 plus 5.

   Passes when: #out should show 7.

5. 5.A named function expressionexercise · medium · 10 min · practice plan

   Use a named function expression to work out factorial of 5.

   Passes when: #out should show 120.

6. 6.Fix the missing assignmentbug fix · easy · 8 min

   The function is never stored, so the variable holds nothing.

   Passes when: #out should show 32.

7. 7.Fix the call before the definitionbug fix · easy · 8 min · practice plan

   A function expression cannot be used above the line that creates it.

   Passes when: #out should show Ready.

8. 8.Fix the wrong function passedbug fix · easy · 8 min · practice plan

   The doubling function was passed to map instead of the tripling one.

   Passes when: #out should show 3,6,9.

9. 9.Fix the wrong method namebug fix · easy · 8 min · practice plan

   The object has no method by that name.

   Passes when: #out should show 7.

10. 10.Fix the missing base casebug fix · easy · 8 min · practice plan

    Without a stopping point the recursion never ends.

    Passes when: #out should show 120.

Between them these tasks cover Function expressions, Anonymous functions and Functions as values.

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