Interview questions in Mobile Dev, page 4
Why Text inherits styles but View does not
Nested Text inherits text styles because it maps to platform attributed-text rendering, while Views are independent layout boxes with no style cascade.
What is a closure capture list? Explain [weak self] versus [unowned self].
Define capture lists, contrast [weak self] safe optionality against [unowned self] crash risk, and match each to lifetime guarantees.
Difference between final and const Dart class properties?
This tests your grasp of Dart's compile-time versus runtime constant model. A strong answer contrasts final variables set once with static const compile-time values, notes const is implicitly final, gives examples. Red flag: const as non-static instance field.
What is a suspend function in Kotlin and its compiler rules?
This tests your understanding of suspendable computations and compiler transformation. A strong answer notes non-blocking suspension, the call-from-suspend-context rule, and compiler support for pausing and resuming. A red flag is claiming they block threads.
What is a `suspend` function in Kotlin?
Tests your grasp of Kotlin's core concurrency primitive. A suspend function can pause and resume. It must be called from another suspend function or a coroutine builder.
What is a Kotlin `suspend` function and how does it work?
Tests your grasp of Kotlin's non-blocking concurrency. A great answer defines a suspend function as pausable, states its two calling rules (from another suspend function or coroutine builder), and mentions the compiler's CPS transformation.
How StyleSheet.create reduces styling overhead
StyleSheet styles are created once with stable references, so identical renders skip reallocation and reduce diffing and serialization work; inline literals allocate new objects each render…
Explain the difference between Kotlin's let, run, with, apply, and also
Group by this (apply, run, with) vs it (let, also), then by return type.
Explain Copy-on-Write in Swift and implement it for custom structs
Tests value semantics with reference storage and uniqueness checks. A strong answer explains CoW delays copy until mutation via isKnownUniquelyReferenced, lists custom steps: wrap, read, check, clone. Red flag: assuming structs are automatically CoW.
Deduplicate a List of emails in Dart
Tests knowledge of Dart's Set semantics and LinkedHashSet insertion order. The idiomatic solution is emails.toSet().toList(), which deduplicates in O(n) time while preserving order. Avoid manual loops with contains, which are O(n^2) and unidiomatic.
Explain Kotlin's scope functions: let, run, with, apply, also
This tests your grasp of idiomatic Kotlin and the two key differentiators: context object (this/it) and return value (object/lambda result). A great answer defines these axes, categorizes each function, and provides a clear example.
Explain Kotlin's five scope functions: let, run, with, apply, also
This tests your grasp of idiomatic Kotlin. A great answer categorizes functions by their context object (this/it) and return value (object/lambda result). Provide a clear use case for apply (object configuration).
Controlled TextInput with value and onChangeText
Store input text in state, bind value to that state, and update state in onChangeText so React is the single source of truth.
How does Swift async/await improve on completion handlers?
Tests structured concurrency mastery over callback control flow. A strong answer covers inversion of control, suspension points as yield locations, and Tasks as parent-child units.
What are the key differences between Dart extends, implements, and with?
This tests your grasp of Dart's inheritance, interface, and mixin models. extends gives single inheritance; implements forces full reimplementation; with injects shared behavior.
How does Structured Concurrency handle cancellations and exceptions?
This tests scope-bound lifecycle management preventing leaks. Cover scope cancellation cascading to children, exceptions propagating up to cancel siblings, and launch or async requiring a scope. A red flag is treating coroutines as fire-and-forget threads.
Structured Concurrency in Kotlin Coroutines
Tests your understanding of coroutine lifecycles and error handling. A good answer defines the parent-child relationship, then explains how cancellation and exceptions propagate through the scope. A red flag is simply calling it a way to 'group' coroutines.
Explain Structured Concurrency in Kotlin Coroutines
Tests your grasp of coroutine lifecycle management. A great answer defines the parent-child relationship within a CoroutineScope, explains cancellation propagation, and details how exceptions cancel the entire hierarchy.
Button vs TouchableOpacity vs Pressable
Button is minimal and platform-styled with limited customization; TouchableOpacity wraps children with an opacity fade; Pressable is the modern, flexible primitive exposing rich press states.
Difference between .xcodeproj and .xcworkspace, and when to use a workspace
Tests your mental model of Xcode build containers. A project defines one buildable unit; a workspace groups multiple projects so they build together and share derived data. Use it for package managers or modular codebases.
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