User properties in Firebase - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to set a user property named 'favorite_color' with the value 'blue'.

Firebase

firebase.analytics().setUserProperties({ [1]: 'blue' });

Drag options to blanks, or click blank then click option'

Asession_duration

Buser_id

Cfavorite_color

Devent_name

Attempts:

3 left

💡 Hint

Common Mistakes

Using event names instead of user property names.

Using reserved keywords like 'user_id' incorrectly.

The setUserProperties method requires the property name as the key. Here, 'favorite_color' is the correct user property name.

2fill in blank

medium

Complete the code to set the user property 'membership_level' to 'gold'.

Firebase

firebase.analytics().setUserProperties({ [1]: 'gold' });

Drag options to blanks, or click blank then click option'

Amembership_level

Buser_status

Cpurchase_amount

Dlast_login

Attempts:

3 left

💡 Hint

Common Mistakes

Using unrelated property names.

Confusing user properties with event parameters.

To set a user property, use the exact property name as the key. Here, 'membership_level' is the correct key.

3fill in blank

hard

Fix the error in the code to correctly set the user property 'preferred_language' to 'en'.

Firebase

firebase.analytics().setUserProperties({ [1]: 'en' });

Drag options to blanks, or click blank then click option'

Apreferred_language

Bpreferred-language

CPreferredLanguage

Dlanguage_preferred

Attempts:

3 left

💡 Hint

Common Mistakes

Using hyphens instead of underscores.

Using camelCase or PascalCase instead of snake_case.

User property names must use underscores and lowercase letters. 'preferred_language' is the correct format.

4fill in blank

hard

Fill both blanks to set user properties 'age' to 30 and 'subscription_status' to 'active'.

Firebase

firebase.analytics().setUserProperties({ [1]: 30, [2]: 'active' });

Drag options to blanks, or click blank then click option'

Aage

Bsubscription_status

Cuser_age

Dstatus

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect or shortened property names.

Mixing up the order of properties.

The user property keys are 'age' and 'subscription_status' as given. Use these exact keys to set the properties.

5fill in blank

hard

Fill all three blanks to set user properties: 'gender' to 'female', 'level' to 'beginner', and 'notifications_enabled' to true.

Firebase

firebase.analytics().setUserProperties({ [1]: 'female', [2]: 'beginner', [3]: true });

Drag options to blanks, or click blank then click option'

Agender

Blevel

Cbeginner

Dnotifications_enabled

Attempts:

3 left

💡 Hint

Common Mistakes

Putting boolean values inside quotes.

Using incorrect property names.

Set the user properties using the exact keys and values: 'gender', 'level', and 'notifications_enabled'. Note that 'notifications_enabled' is a boolean and should not be in quotes here.

Practice

1. What is the main purpose of user properties in Firebase Analytics?

easy

A. To store simple information about users for better app insights

B. To authenticate users securely

C. To send push notifications to users

D. To manage database access rules

Solution

1. Step 1: Understand user properties role

   User properties are used to store simple info about users, like preferences or demographics.

2. Step 2: Differentiate from other Firebase features

   Authentication, notifications, and database rules serve different purposes unrelated to user properties.

3. Final Answer:

   To store simple information about users for better app insights -> Option A

4. Quick Check:

   User properties = store user info for insights [OK]

Hint: User properties = user info for insights, not security or messaging [OK]

Common Mistakes:

• Confusing user properties with authentication
• Thinking user properties send notifications
• Mixing user properties with database rules

2. Which of the following is the correct way to set a user property named favorite_color to blue in Firebase Analytics?

easy

A. firebase.analytics().setUserProperty('favorite_color', 'blue');

B. firebase.analytics().setUserProperties('favorite_color', 'blue');

C. firebase.analytics().setUserProperties({favorite_color: 'blue'});

D. firebase.analytics().setUserProperty({favorite_color: 'blue'});

Solution

1. Step 1: Recall correct method signature

   The correct method to set multiple user properties is setUserProperties with an object of key-value pairs.

2. Step 2: Check method usage

   firebase.analytics().setUserProperties({favorite_color: 'blue'}); uses setUserProperties with an object, which is correct. The other options misuse method names or parameters.

3. Final Answer:

   firebase.analytics().setUserProperties({favorite_color: 'blue'}); -> Option C

4. Quick Check:

   Use setUserProperties with object = firebase.analytics().setUserProperties({favorite_color: 'blue'}); [OK]

Hint: Use setUserProperties with an object for key-value pairs [OK]

Common Mistakes:

• Using setUserProperty instead of setUserProperties
• Passing key and value as separate arguments incorrectly
• Passing an object to setUserProperty

3. Consider this code snippet:

firebase.analytics().setUserProperties({membership: 'gold'});
console.log(userProperties.membership);

What will be the output of console.log?

medium

A. 'gold'

B. undefined

C. null

D. Error: userProperties is not defined

Solution

1. Step 1: Analyze variable usage

   The code calls setUserProperties but tries to log userProperties.membership.

2. Step 2: Check if userProperties is defined

   No variable named userProperties is declared or imported, so accessing it causes a ReferenceError.

3. Final Answer:

   Error: userProperties is not defined -> Option D

4. Quick Check:

   Undefined variable access = ReferenceError [OK]

Hint: User properties set in Firebase, not accessible as local variable [OK]

Common Mistakes:

• Assuming userProperties is a local object
• Expecting immediate local access after setUserProperties call
• Confusing Firebase API with local variables

4. You wrote this code to set a user property:

firebase.analytics().setUserProperties('plan', 'premium');

But it does not work. What is the error?

medium

A. The method name should be setUserProperty (singular)

B. setUserProperties expects an object, not two string arguments

C. User property keys cannot be strings

D. Firebase Analytics does not support user properties

Solution

1. Step 1: Review method signature

   setUserProperties requires a single object argument with key-value pairs, not separate strings.

2. Step 2: Identify correct usage

   Passing two strings causes the method to fail because it expects an object like {plan: 'premium'}.

3. Final Answer:

   setUserProperties expects an object, not two string arguments -> Option B

4. Quick Check:

   setUserProperties needs object argument [OK]

Hint: setUserProperties takes one object, not separate strings [OK]

Common Mistakes:

• Passing key and value as separate arguments
• Using wrong method name
• Thinking keys can't be strings

5. You want to track users by their subscription tier and preferred language using user properties. Which code snippet correctly sets both properties at once?

hard

A. firebase.analytics().setUserProperties({subscription: 'premium', language: 'en'});

B. firebase.analytics().setUserProperties('subscription', 'premium');
firebase.analytics().setUserProperties('language', 'en');

C. firebase.analytics().setUserProperty({subscription: 'premium', language: 'en'});

D. firebase.analytics().setUserProperties(['subscription', 'premium'], ['language', 'en']);

Solution

1. Step 1: Understand setting multiple properties

   To set multiple user properties at once, pass a single object with all key-value pairs to setUserProperties.

2. Step 2: Evaluate each option

   firebase.analytics().setUserProperties({subscription: 'premium', language: 'en'}); correctly uses an object with both properties. firebase.analytics().setUserProperties('subscription', 'premium'); firebase.analytics().setUserProperties('language', 'en'); incorrectly calls the method twice with wrong argument types. firebase.analytics().setUserProperty({subscription: 'premium', language: 'en'}); uses wrong method name. firebase.analytics().setUserProperties(['subscription', 'premium'], ['language', 'en']); passes arrays instead of an object.

3. Final Answer:

   firebase.analytics().setUserProperties({subscription: 'premium', language: 'en'}); -> Option A

4. Quick Check:

   One object with all properties = firebase.analytics().setUserProperties({subscription: 'premium', language: 'en'}); [OK]

Hint: Set multiple properties in one object with setUserProperties [OK]

Common Mistakes:

• Calling setUserProperties multiple times with wrong args
• Using setUserProperty instead of setUserProperties
• Passing arrays instead of an object