Project structure in iOS Swift - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Understanding the role of Info.plist in an iOS project

What is the primary purpose of the Info.plist file in an iOS Swift project?

A It contains the Swift source code for the app's main view controller.

B It stores configuration data like app permissions and display name used by the system.

C It manages the app's user interface layout and constraints.

D It holds the compiled binary executable of the app.

💡 Hint

Think about what the system needs to know about your app before running it.

Info.plist is a property list file that holds key-value pairs describing app settings like permissions, app name, icon files, and launch screen info. It is not source code or UI layout.

❓ ui_behavior

intermediate

Locating the main storyboard in an iOS project

In a typical iOS Swift project using storyboards, where is the main storyboard file referenced so the app knows which UI to load first?

A In the Info.plist file under the key "UIMainStoryboardFile".

B Inside the AppDelegate.swift file as a string constant.

C In the Assets.xcassets folder as an image set.

D In the LaunchScreen.storyboard file.

💡 Hint

This setting tells the system which storyboard to load at app launch.

The Info.plist file contains the key "UIMainStoryboardFile" which points to the main storyboard file. This tells iOS which UI to load first.

❓ lifecycle

advanced

Order of files executed at app launch

Which sequence correctly describes the order of execution when an iOS Swift app launches?

A 2, 1, 3, 4

B 3, 1, 2, 4

C 1, 2, 3, 4

D 1, 3, 2, 4

💡 Hint

Think about what happens first: system call, app delegate, UI loading, then showing window.

UIApplicationMain is the entry point that sets up the app. Then AppDelegate's launch method runs. After that, the main storyboard loads the UI, and finally the window is shown.

❓ navigation

advanced

Where to add new Swift files for view controllers

In a well-organized iOS Swift project, where should you place new Swift files that define view controllers?

A In the Info.plist file as embedded code.

B Inside the LaunchScreen.storyboard file.

C Directly inside the Assets.xcassets folder.

D Inside a dedicated folder named "ViewControllers" or similar within the project directory.

💡 Hint

Think about keeping code files organized by their role.

Source code files like view controllers should be in dedicated folders for clarity and maintenance. Assets and storyboards are for images and UI layouts, not code.

🔧 Debug

expert

Why does the app crash on launch after renaming the main storyboard file?

You renamed your main storyboard file from "Main.storyboard" to "Start.storyboard" but did not update any other files. What is the most likely cause of the app crashing on launch?

A The Info.plist still references "Main" as the main storyboard file, causing a missing file error.

B The AppDelegate.swift file must be renamed to match the storyboard name.

C The Assets.xcassets folder needs to be updated with the new storyboard name.

D The LaunchScreen.storyboard must be deleted to avoid conflicts.

💡 Hint

Check where the system looks for the initial UI file.

The Info.plist file still points to the old storyboard name "Main". Since the file was renamed to "Start", the app cannot find the storyboard and crashes.