mobile-app-debugging

# Mobile App Debugging Debug mobile applications across iOS, Android, and cross-platform frameworks. ## iOS Debugging (Xcode) ```swift // Breakpoint with condition // Right-click breakpoint > Edit > Condition: userId == "123" // LLDB commands po variable // Print object p expression // Evaluate expression bt // Backtrace ``` ### Memory Debugging - Use Memory Graph Debugger to find retain cycles - Enable Zombie Objects for use-after-free bugs - Profile with Instruments > Leaks ## Android Debugging (Android Studio) ```kotlin // Logcat filtering Log.d("TAG", "Debug message") Log.e("TAG", "Error", exception) // Filter: tag:MyApp level:error ``` ### Common Issues - ANR: Check main thread blocking - OOM: Profile with Memory Profiler - Layout issues: Use Layout Inspector ## React Native ```javascript // Remote debugging // Shake device > Debug JS Remotely // Console logging console.log('Debug:', variable); console.warn('Warning'); console.error('Error'); // Performance Monitor // Shake > Show Perf Monitor // Target: 60 FPS, <16ms per frame ``` ## Network Debugging ```javascript // Intercept requests XMLHttpRequest.prototype._send = XMLHttpRequest.prototype.send; XMLHttpRequest.prototype.send = function() { console.log('Request:', this._url); this._send.apply(this, arguments); }; ``` ## Debug Checklist - [ ] Test on physical devices (not just simulators) - [ ] Test on older device models - [ ] Simulate slow 3G network - [ ] Test offline mode - [ ] Check memory under load - [ ] Test rotation and safe areas - [ ] Verify 60 FPS target ## Performance Targets | Metric | Target | |--------|--------| | Frame rate | 60 FPS (16ms/frame) | | Memory | <100MB | | App launch | <2 seconds |