React Native Certification

Syllabus

Every paper is drawn to this mix, so the weights are a promise rather than a guide. The bars show each area's share of the 50 questions.

• What React Native is, and Expo vs. bare workflow

  4 Q·8%

  One JavaScript codebase rendering real native UI (not a WebView), what that buys you over a hybrid app, and Expo's managed workflow versus the bare React Native CLI.

• Project structure, entry point, components and hooks

  4 Q·8%

  Typical project shape, the app's entry point, and that React Native components are plain React function components using the same Hooks as React DOM.

• Core components: View, Text, Image and Flexbox layout

  4 Q·8%

  View, Text (and the rule that all text must live inside one), Image's source prop, and Flexbox layout including React Native's column default flex-direction.

• StyleSheet and styling patterns

  3 Q·6%

  Why StyleSheet.create exists, unitless density-independent style numbers, combining styles with an array, and inline styles for dynamic values.

• ScrollView vs. FlatList, safe areas and responsive layout

  4 Q·8%

  When to reach for ScrollView versus FlatList, safe-area-aware layout around notches and system bars, and responsive sizing across devices.

• Touch handling, Pressable and forms

  3 Q·6%

  Pressable as the modern touch-response component, the function-as-style press-feedback pattern, and TextInput's controlled value/onChangeText pattern.

• FlatList virtualization, SectionList and pull-to-refresh

  4 Q·8%

  What virtualization means, why keyExtractor matters, performance-tuning props, SectionList for grouped data, and pull-to-refresh via refreshing/onRefresh.

• Navigation concepts: stack, tab and drawer navigators

  3 Q·6%

  React Navigation as the ecosystem standard, and the stack, tab and drawer navigator patterns, including nesting them.

• Passing params, conditional navigation and deep linking

  4 Q·8%

  Passing and reading screen params, switching an entire navigator based on auth state, and what a deep link is and how it maps a URL to a screen.

• Platform differences: Platform.OS and Platform.select

  3 Q·6%

  Platform.OS and Platform.select, platform-specific file extensions, and real platform differences like shadow styling and the Android back button.

• Permissions, native modules, the bridge and JSI

  4 Q·8%

  Runtime permission requests, what a native module is for, the historical asynchronous bridge, and JSI's more direct JS-native communication.

• Push notifications conceptually

  2 Q·4%

  The device-token registration and delivery pipeline through APNs/FCM, and Expo's unified push service as one current option.

• Avoiding re-renders and animations with the native driver

  4 Q·8%

  The same re-render model as React with higher visual stakes on a phone, and what useNativeDriver: true changes about where animation frames run.

• The New Architecture, debugging, testing and shipping

  4 Q·8%

  Fabric, TurboModules and JSI as the platform's current direction, debugging and testing tools, and what it takes to build, sign and ship to the app stores.

Three questions from the bank

Representative of the mix and difficulty — answer visible, shown here to calibrate expectations rather than test you.

1. Sample 1·What React Native is, and Expo vs. bare workflow

   What fundamentally distinguishes React Native from a 'hybrid' app that wraps a website in a native WebView?

   • React Native renders actual native UI components (like a native view on iOS and Android) through its host platform, not HTML displayed inside an embedded browser
   • BReact Native apps are written in Swift and Kotlin instead of JavaScript
   • CReact Native only works on Android, not iOS
   • DHybrid apps and React Native both use the same rendering pipeline, so there is no real difference

   Why: React Native's core promise is that your JS drives real native views, not a WebView host as in older hybrid approaches. Rendering isn't HTML repainted in a browser engine — it's genuine platform UI widgets, which is why RN apps feel and perform like native apps rather than a website in a frame. RN is written in JS/TS (not compiled Swift/Kotlin source), and it targets both iOS and Android.

2. Sample 2·Project structure, entry point, components and hooks

   In a bare React Native CLI project, what do the ios/ and android/ directories contain?

   • The native Xcode and Android Studio projects that embed the JS bundle and provide the native shell the app runs in
   • BCompiled JavaScript output only, with no native code
   • CUnit tests for the JS codebase
   • DConfiguration for Expo config plugins only

   Why: Bare RN gives you full native projects — an Xcode project under ios/ and a Gradle/Android Studio project under android/ — that can be opened and edited directly, unlike the managed Expo workflow, where these are generated and normally hidden.

3. Sample 3·Core components: View, Text, Image and Flexbox layout

   What happens when a bare string is rendered directly inside a <View>, the way text might sit directly inside a <div> on the web?

   • It's invalid — React Native requires all text to be wrapped in a Text component; View cannot render raw text directly the way a web div can
   • BIt renders fine, identically to a div, since View is RN's div equivalent in every respect
   • CIt renders but the string is silently ignored
   • DIt is automatically wrapped in a Text component behind the scenes with no warning needed

   Why: This is one of RN's sharpest departures from the web: unlike a div with text directly inside it, a bare string as a child of View is invalid — RN requires any text content to be explicitly wrapped in Text. There's no silent auto-wrapping, which is the tempting-but-wrong belief for someone assuming RN behaves like the web here.

What sitting it is like