All topics

💾 Memory management: iOS interview questions

1. Memory management Junior PRO
2. Reference counting Junior PRO
3. ARC Junior PRO
4. MRC Middle PRO
5. Freeing memory in MRC Middle PRO
6. autorelease vs release? Middle PRO
7. How are weak references implemented in Swift? Senior PRO
8. Describe the lifecycle of an object in Swift. Senior PRO
9. When can you skip [weak self] in a closure? Middle PRO
10. When do you need an autoreleasepool in Swift? Middle PRO
11. What if the project uses ARC but you need non-ARC classes? Middle PRO
12. How do the stack and the heap work? Junior PRO
13. Each thread has its own stack — what about the heap? Junior PRO
14. What is a side table and when is it created? Senior PRO
15. Can a reference type live on the stack? Senior PRO
16. How many bytes per memory access? What is a word? Middle PRO
17. What is MemoryLayout? size, stride, alignment Senior PRO
18. Does the order of struct fields affect its size? Senior PRO
19. What is virtual memory? Where do code, stack and heap physically live? Senior PRO
20. How do file-backed pages differ from anonymous? Senior PRO
21. Why is there no swap in iOS? What happens under memory pressure? Senior PRO
22. What is jetsam? How does the system decide which app to kill? Senior PRO
23. How do you diagnose a memory leak? Middle PRO
24. Dirty vs resident vs virtual memory? Senior PRO
25. [weak self] vs [unowned self] — when to use which? Middle PRO