User properties in Firebase - Commands & Configuration

Introduction

User properties let you describe your app users with simple labels. This helps you understand who your users are and how they behave.

When you want to group users by age or location to see how different groups use your app.

When you want to track if users are premium subscribers or free users.

When you want to personalize app content based on user interests.

When you want to filter analytics reports to focus on specific user segments.

When you want to create marketing campaigns targeting users with certain traits.

Commands

This command sets user properties 'age' and 'subscription' for the user with ID 'user123'. It helps label the user for analytics.

Terminal

firebase analytics set-user-properties --user-id user123 --properties "age=25,subscription=premium"

Expected Output

User properties set for user ID user123

→

--user-id - Specifies the user ID to assign properties to

→

--properties - Defines the key-value pairs of user properties

This command retrieves the user properties for the user with ID 'user123' to verify what labels are set.

Terminal

firebase analytics get-user-properties --user-id user123

Expected Output

age: 25

subscription: premium

→

--user-id - Specifies the user ID to fetch properties for

Key Concept

If you remember nothing else from this pattern, remember: user properties are simple labels that help you understand and segment your app users.

Common Mistakes

Trying to set user properties without specifying the user ID

The system does not know which user to label, so the command fails or has no effect.

Always include the --user-id flag with the correct user identifier.

Using invalid characters or spaces in property keys or values

User properties must be simple strings without spaces or special characters, otherwise they are rejected.

Use only letters, numbers, and underscores in keys and values without spaces.

Summary

Use the firebase analytics CLI to set user properties with --user-id and --properties flags.

Verify user properties by retrieving them with the get-user-properties command.

User properties help label users for better analytics and targeted actions.

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