Returning a pointer to an automatic variable

by

It won’t cause a memory leak. It’ll cause a dangling reference. The local variable is allocated on the stack and will be freed as soon as it goes out of scope. As a result, when the function ends, the pointer you are returning no longer points to a memory you own. This is not a memory leak (memory leak is when you allocate some memory and don’t free it).

[Update]:
To be able to return an array allocated in a function, you should allocate it outside stack (e.g. in the heap) like:

char *test() {
    char* arr = malloc(100);
    arr[0] = 'M';
    return arr;
}

Now, if you don’t free the memory in the calling function after you finished using it, you’ll have a memory leak.

More Related Contents:

  1. Which library has power function? [closed]
  2. Why is this segfaulting? Can someone explain the valgrind error?
  3. error: incompatible types for a function that returns float in C
  4. Passing an array as an argument to a function in C
  5. How do you pass a function as a parameter in C?
  6. C function syntax, parameter types declared after parameter list
  7. Nested function in C
  8. Why does a C-Array have a wrong sizeof() value when it’s passed to a function? [duplicate]
  9. Function pointers and address of a function
  10. Alternative (K&R) C syntax for function declaration versus prototypes
  11. Allocate memory 2d array in function C
  12. Macro vs Function in C
  13. Passing multidimensional arrays as function arguments in C
  14. Proper usage of realloc()
  15. X,Y passing size for the array in C function
  16. Why must the variable used to hold getchar’s return value be declared as int?
  17. strcpy() return value
  18. What is this strange function definition syntax in C? [duplicate]
  19. What does ‘sizeof (function name)’ return?
  20. C function calls: Understanding the “implicit int” rule
  21. Returning Arrays/Pointers from a function
  22. When is an array name or a function name ‘converted’ into a pointer ? (in C)
  23. Manipulate multidimensional array in a function
  24. Returning from a void function [closed]
  25. Function pointer as a member of a C struct
  26. Regex to pull out C function prototype declarations?
  27. Pass by reference in C
  28. C declaration from standard signal Library
  29. Need for prefixing a function with (void)
  30. How sqrt() of GCC works after compiled? Which method of root is used? Newton-Raphson?

Leave a Comment