Analytics and Crashlytics in iOS Swift - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ ui_behavior

intermediate

What happens when you log an event with Firebase Analytics in Swift?

Consider this Swift code snippet that logs a custom event using Firebase Analytics. What is the expected behavior after this code runs?

iOS Swift

import FirebaseAnalytics

Analytics.logEvent("purchase", parameters: ["item_id": "sku123", "price": 9.99])

A The event "purchase" with parameters is sent to Firebase Analytics and appears in the Firebase console dashboard.

B The app crashes because the logEvent method requires a completion handler.

C Nothing happens because you must call Analytics.start() before logging events.

D The event is logged locally but never sent to Firebase servers.

💡 Hint

Think about how Firebase Analytics handles event logging and reporting.

Calling Analytics.logEvent sends the event data asynchronously to Firebase Analytics. The event will appear in the Firebase console after some processing time.

❓ lifecycle

intermediate

When should you initialize Firebase Crashlytics in an iOS app?

You want to capture crashes in your iOS app using Firebase Crashlytics. At which point in the app lifecycle should you initialize Crashlytics to ensure it captures all crashes?

A After the user logs in successfully.

B In the viewDidLoad() method of the first view controller.

C Right before the app enters the background state.

D In the AppDelegate's application(_:didFinishLaunchingWithOptions:) method before returning true.

💡 Hint

Crashlytics needs to be ready as early as possible to catch startup crashes.

Initializing Crashlytics in application(_:didFinishLaunchingWithOptions:) ensures it starts monitoring crashes from app launch onward.

🔧 Debug

advanced

Why does this Crashlytics custom key not appear in the Firebase console?

You added this code to set a custom key in Crashlytics, but the key-value pair does not show up in the Firebase Crashlytics dashboard. What is the most likely reason?

iOS Swift

import FirebaseCrashlytics

Crashlytics.crashlytics().setCustomValue("premium", forKey: "user_type")

A The method setCustomValue is deprecated and does not work anymore.

B The app has not crashed after setting the custom key, so Crashlytics has not sent the data yet.

C You must call Crashlytics.crashlytics().send() manually to upload keys.

D Custom keys only appear if you set them before FirebaseApp.configure() is called.

💡 Hint

Think about when Crashlytics uploads crash reports and associated data.

Crashlytics uploads custom keys only when a crash occurs. Without a crash, the keys are not sent or visible in the dashboard.

🧠 Conceptual

advanced

How does Firebase Analytics handle user privacy and data collection on iOS?

Which statement correctly describes Firebase Analytics behavior regarding user privacy on iOS devices?

A Firebase Analytics ignores user privacy settings and always collects device identifiers.

B You must manually disable Firebase Analytics if the user opts out of tracking; it does not handle this automatically.

C Firebase Analytics automatically respects the iOS App Tracking Transparency (ATT) framework and disables IDFA collection if the user denies permission.

D Firebase Analytics only collects data when the app is in the foreground.

💡 Hint

Consider Apple's privacy rules and how Firebase integrates with them.

Firebase Analytics integrates with iOS privacy frameworks and respects user consent for tracking, disabling IDFA collection if permission is denied.

❓ navigation

expert

What is the effect of calling Crashlytics.crashlytics().crash() in your app?

You add the following line in your app code during testing. What happens when this line executes?

iOS Swift

Crashlytics.crashlytics().crash()

A The app immediately crashes, generating a crash report sent to Firebase Crashlytics on next launch.

B The app logs a non-fatal error but continues running without interruption.

C The app throws a runtime exception that can be caught by a try-catch block.

D Nothing happens because this method is only a placeholder and does not cause a crash.

💡 Hint

This method is used to test Crashlytics crash reporting.

Calling crash() forces the app to crash immediately, which helps test Crashlytics crash reporting functionality.

Practice

1. What is the main purpose of using Analytics in an iOS app?

easy

A. To track user actions and app usage patterns

B. To report app crashes and errors

C. To improve app performance by optimizing code

D. To manage app permissions and privacy settings

Solution

1. Step 1: Understand Analytics role

   Analytics collects data about how users interact with the app, like button taps or screen views.

2. Step 2: Differentiate from Crashlytics

   Crashlytics focuses on crash reports, not user behavior tracking.

3. Final Answer:

   To track user actions and app usage patterns -> Option A

4. Quick Check:

   Analytics = user action tracking [OK]

Hint: Analytics tracks usage; Crashlytics tracks crashes [OK]

Common Mistakes:

• Confusing Analytics with Crashlytics
• Thinking Analytics fixes crashes
• Assuming Analytics manages permissions

2. Which Swift code snippet correctly logs a custom event named "purchase_complete" using Firebase Analytics?

easy

A. Analytics.logEvent("purchase_complete", parameters: [:])

B. Analytics.logEvent(purchase_complete, parameters: [:])

C. Analytics.logEvent("purchase_complete", parameters: "nil")

D. Analytics.logEvent('purchase_complete')

Solution

1. Step 1: Check method signature

   The correct method requires event name as a string and parameters as a dictionary (can be empty).

2. Step 2: Validate syntax correctness

   Analytics.logEvent("purchase_complete", parameters: [:]) uses a string event name and an empty dictionary, matching the required syntax.

3. Final Answer:

   Analytics.logEvent("purchase_complete", parameters: [:]) -> Option A

4. Quick Check:

   Correct syntax = Analytics.logEvent("purchase_complete", parameters: [:]) [OK]

Hint: Event name as string, parameters as dictionary [OK]

Common Mistakes:

• Missing quotes around event name
• Passing nil instead of dictionary
• Omitting parameters argument

3. Given the following Swift code snippet using Crashlytics, what will happen when a crash occurs?

Crashlytics.crashlytics().log("User tapped buy button")
fatalError("Simulated crash")

medium

A. The app crashes but the log message is lost

B. The log message causes a runtime error

C. The app does not crash because log prevents it

D. The log message is sent to Crashlytics before the app crashes

Solution

1. Step 1: Understand Crashlytics log behavior

   Calling log records a message that is sent to Crashlytics on next app launch after a crash.

2. Step 2: Analyze crash trigger

   fatalError causes an immediate crash, but the log message is preserved for reporting.

3. Final Answer:

   The log message is sent to Crashlytics before the app crashes -> Option D

4. Quick Check:

   Crashlytics logs persist through crash [OK]

Hint: Crashlytics logs survive crashes for later reporting [OK]

Common Mistakes:

• Assuming logs are lost on crash
• Thinking log prevents crash
• Confusing log with error throwing

4. You added Crashlytics to your app but crash reports are not showing up in the Firebase console. Which of these is the most likely cause?

medium

A. You used fatalError instead of assert

B. You forgot to call Crashlytics.crashlytics().setCrashlyticsCollectionEnabled(true)

C. You did not import UIKit in your Swift file

D. You called Analytics.logEvent instead of Crashlytics methods

Solution

1. Step 1: Check Crashlytics setup requirements

   Crashlytics requires enabling data collection explicitly or via Info.plist to send crash reports.

2. Step 2: Identify missing configuration

   Not calling setCrashlyticsCollectionEnabled(true) disables crash report sending.

3. Final Answer:

   You forgot to call Crashlytics.crashlytics().setCrashlyticsCollectionEnabled(true) -> Option B

4. Quick Check:

   Enable collection to send crash reports [OK]

Hint: Enable Crashlytics collection to receive reports [OK]

Common Mistakes:

• Confusing Analytics logging with Crashlytics setup
• Missing import statements
• Thinking crash method choice affects reporting

5. You want to log a user property "user_level" with value "gold" in Firebase Analytics and also log a non-fatal error in Crashlytics when a payment fails. Which Swift code snippet correctly does both?

hard

A. Analytics.setUserProperty("user_level", forName: "gold")
Crashlytics.crashlytics().record(error: Error("Payment failed"))

B. Analytics.logEvent("user_level", parameters: ["gold"])
Crashlytics.crashlytics().log("Payment failed")

C. Analytics.setUserProperty("gold", forName: "user_level")
Crashlytics.crashlytics().record(error: NSError(domain: "Payment", code: 1, userInfo: nil))

D. Analytics.setUserProperty("gold", forName: "user_level")
Crashlytics.crashlytics().log("Payment failed")

Solution

1. Step 1: Set user property correctly

   Use setUserProperty(_:forName:) with value first, then property name.

2. Step 2: Log non-fatal error properly

   Use record(error:) with an NSError instance to report non-fatal errors.

3. Final Answer:

   Analytics.setUserProperty("gold", forName: "user_level") Crashlytics.crashlytics().record(error: NSError(domain: "Payment", code: 1, userInfo: nil)) -> Option C

4. Quick Check:

   User property + non-fatal error = Analytics.setUserProperty("gold", forName: "user_level") Crashlytics.crashlytics().record(error: NSError(domain: "Payment", code: 1, userInfo: nil)) [OK]

Hint: User property value first, use record(error:) for non-fatal errors [OK]

Common Mistakes:

• Swapping user property name and value
• Using log() instead of record(error:) for errors
• Passing wrong types to methods