Find malloc() array length in C? [duplicate]

by

In the second case, num is not an array, is a pointer. sizeof is giving you the size of the pointer, which seems to be 8 bytes on your platform.

There is no way to know the size of a dynamically allocated array, you have to save it somewhere else. sizeof looks at the type, but you can’t obtain a complete array type (array type with a specified size, like the type int[5]) from the result of malloc in any way, and sizeof argument can’t be applied to an incomplete type, like int[].

More Related Contents:

  1. Using malloc for allocation of multi-dimensional arrays with different row lengths
  2. Difference between array type and array allocated with malloc
  3. Freaky way of allocating two-dimensional array?
  4. How to use realloc in a function in C
  5. Dynamically create an array of strings with malloc
  6. Getting the size of a malloc only with the returned pointer
  7. Variable Sized Arrays vs calloc in C
  8. Malloc and array index confusion in C
  9. Is it possible to use notation [] with pointers in C?
  10. C array pointer increment
  11. Why this program is crashing?
  12. C-programming board game [duplicate]
  13. Returning an array using C
  14. Getting a stack overflow exception when declaring a large array
  15. How do I work with dynamic multi-dimensional arrays in C?
  16. Overriding ‘malloc’ using the LD_PRELOAD mechanism
  17. What is the maximum size of an array in C?
  18. How does GCC implement variable-length arrays?
  19. Pointer address in a C multidimensional array
  20. Incompatible implicit declaration of built-in function ‘malloc’
  21. Performance of 2-dimensional array vs 1-dimensional array
  22. Malloc a 2D array in C [duplicate]
  23. initializing an array of ints
  24. Use of cudamalloc(). Why the double pointer?
  25. Literal string initializer for a character array
  26. dynamic allocating array of arrays in C
  27. How can I work with dynamically-allocated arbitrary-dimensional arrays?
  28. Why does scanf() need & operator (address-of) in some cases, and not others? [duplicate]
  29. Code for malloc and free
  30. How can I malloc a struct array inside a function? Code works otherwise

Leave a Comment