Create an object — practice exercise

What you'll be asked to do

1. 1.Create an objectexercise · easy · 10 min

   Create a person object with a name and show the name.

   Passes when: #out should show Ada.

2. 2.Read with bracketsexercise · easy · 10 min · practice plan

   Read a property using a key held in a variable.

   Passes when: #out should show Toyota.

3. 3.Add a propertyexercise · easy · 10 min · practice plan

   Add a year to a car object and show the brand and year together.

   Passes when: #out should show Toyota 2021.

4. 4.Check a missing propertyexercise · easy · 10 min · practice plan

   Show the type of a property that was never set.

   Passes when: #out should show undefined.

5. 5.Delete a propertyexercise · medium · 10 min · practice plan

   Delete one property and show how many are left.

   Passes when: #out should show 1.

6. 6.Fix the dot used with a variable keybug fix · easy · 8 min

   A dot looks for a property literally named key.

   Passes when: #out should show Toyota.

7. 7.Fix the array bracketsbug fix · easy · 8 min · practice plan

   Square brackets make an array, so the named properties are lost.

   Passes when: #out should show Ada.

8. 8.Fix the equals sign in the literalbug fix · easy · 8 min · practice plan

   Object properties use a colon, not an equals sign.

   Passes when: #out should show Toyota 2021.

9. 9.Fix the misspelled propertybug fix · easy · 8 min · practice plan

   The name is read with a typo, so nothing is found.

   Passes when: #out should show Ada.

10. 10.Fix the property never removedbug fix · easy · 8 min · practice plan

    Setting a property to undefined leaves it in place.

    Passes when: #out should show 1.

Between them these tasks cover Object literals, Dot notation and Bracket notation.

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