Order of operations for pre-increment and post-increment in a function argument? [duplicate]

by

Well, there are two things to consider with your example code:

  1. The order of evaluation of function arguments is unspecified, so whether ++a or a++ is evaluated first is implementation-dependent.
  2. Modifying the value of a more than once without a sequence point in between the modifications results in undefined behavior. So, the results of your code are undefined.

If we simplify your code and remove the unspecified and undefined behavior, then we can answer the question:

void xyz(int x) { }

int a = 1;
xyz(a++); // 1 is passed to xyz, then a is incremented to be 2

int a = 1;
xyz(++a); // a is incremented to be 2, then that 2 is passed to xyz

More Related Contents:

  1. C: What is the output of the following code? And please explain [duplicate]
  2. What is the difference between ++i and i++?
  3. Is there a performance difference between i++ and ++i in C?
  4. Pre increment vs Post increment in array
  5. Output of multiple post and pre increments in one statement [duplicate]
  6. Is there a performance difference between i++ and ++i in C++?
  7. Post-increment and Pre-increment concept?
  8. Incrementing in C++ – When to use x++ or ++x?
  9. What is more efficient, i++ or ++i? [duplicate]
  10. Pre- & Post Increment in C#
  11. Array increment operator in C
  12. Post-increment within a self-assignment
  13. ++i or i++ in for loops ?? [duplicate]
  14. How do you type something on the same line of text in C [closed]
  15. how will i pass the path of a file name to void *buffer using c language?
  16. How to create type safe enums?
  17. Why can’t I cast a function pointer to (void *)?
  18. sem_init on OS X
  19. When the main thread exits, do other threads also exit?
  20. How to compile .c file with OpenSSL includes?
  21. Why is printf round floating point numbers up?
  22. Compute fast log base 2 ceiling
  23. Array type char[] is not assignable [duplicate]
  24. Why can I change the value of a const char* variable?
  25. Header per source file
  26. Are constant C expressions evaluated at compile time or at runtime?
  27. Changing a macro at runtime in C
  28. Getting started with Intel x86 SSE SIMD instructions
  29. Do you prefer “if (var)” or “if (var != 0)”? [closed]
  30. C difference between *[] and **

Leave a Comment