Debugging Tips for iOS Developers

Debugging Tips for iOS Developers

Effective debugging saves hours. Here are some practical techniques.

1. Breakpoints and LLDB

• Conditional breakpoints — Right-click a breakpoint → Edit → Add condition
• LLDB commands — po variable to print, frame variable for locals
• Debugger console — Run expressions like po viewModel.items.count

2. Print Debugging (Still Useful)

print("State: \(state), count: \(items.count)")
// Or use dump() for complex types
dump(viewModel)

3. Xcode Instruments

• Time Profiler — Find slow code
• Allocations — Track memory usage
• Leaks — Detect retain cycles

4. SwiftUI Preview Debugging

Use #Preview with different states:

#Preview("Empty state") {
    ContentView(items: [])
}
#Preview("With data") {
    ContentView(items: sampleItems)
}

5. Assert and Precondition

Catch bugs early in development:

assert(index >= 0 && index < items.count, "Invalid index")

---

Stuck on a bug? Sometimes stepping away and rubber-ducking helps. Or check our courses for structured learning.