Checking the size of an object in Objective-C

by

All the compiler knows about is the pointer, which is why you’re getting the size of the pointer back. To see the size of the allocated object, use one of the following code snippets:

With ARC:

#import <malloc/malloc.h>

// ...

NSLog(@"Size of %@: %zd", NSStringFromClass([myObject class]), malloc_size((__bridge const void *) myObject));

Without ARC:

#import <malloc/malloc.h>

// ...

NSLog(@"size of myObject: %zd", malloc_size(myObject));

Mike Ash has a decent write-up about some of the Obj-C runtime internals on his Q&A blog: http://mikeash.com/?page=pyblog/friday-qa-2009-03-13-intro-to-the-objective-c-runtime.html

More Related Contents:

  1. What does sizeof(&array) return?
  2. Why does a C-Array have a wrong sizeof() value when it’s passed to a function? [duplicate]
  3. sizeof() operator in if-statement
  4. Objective-C : BOOL vs bool
  5. What does the ‘array name’ mean in case of array of char pointers?
  6. newbie questions about malloc and sizeof
  7. Why is sizeof considered an operator?
  8. Using sizeof with a dynamically allocated array
  9. Why is this happening with the sizeof operator when comparing with a negative number? [duplicate]
  10. Mixing C functions in an Objective-C class
  11. Objective-C sample code for HMAC-SHA1 [closed]
  12. sizeof with a type or variable
  13. Variably modified array at file scope
  14. size of character array and size of character pointer
  15. In C, why is sizeof(char) 1, when ‘a’ is an int?
  16. How can I print the result of sizeof() at compile time in C?
  17. Limit a double to two decimal places [duplicate]
  18. Why is (sizeof(int) > -1) false? [duplicate]
  19. Is it ok to use “classic” malloc()/free() in Objective-C/iPhone apps?
  20. How can I avoid “duplicate symbol” errors in xcode with shared static libraries?
  21. Using sizeof() on malloc’d memory [duplicate]
  22. Why do I get a warning every time I use malloc?
  23. sizeof single struct member in C
  24. Implementation of sizeof operator
  25. What’s sizeof(size_t) on 32-bit vs the various 64-bit data models?
  26. Reliably determine the number of elements in an array
  27. C -> sizeof string is always 8
  28. Size of pid_t, uid_t, gid_t on Linux
  29. Find size of array without using sizeof
  30. How can I break out of two nested for loops in Objective-C?

Leave a Comment