Output of multiple post and pre increments in one statement [duplicate]

by

The results are undefined. You’re modifying a variable more than once in an expression (or sequence point to be more accurate).

Modifying a variable more than once between sequence points is undefined, so don’t do it.

It might be your compiler, for this particular case decides to evalate
++i + ++i as

  • increment the last ++i , yielding 4, leaving i to be 4
  • increment the first ++i, yielding 5, leaving i to be 5 (as the prior step left i as 4, incrementing it to 5)
  • sum the two values, 4 + 5.

Another compiler, or if you alter the optimization level, or if you change the code slightly, might produce different output.

More Related Contents:

  1. C: What is the output of the following code? And please explain [duplicate]
  2. Why are these constructs using pre and post-increment undefined behavior?
  3. What is the difference between ++i and i++?
  4. Is there a performance difference between i++ and ++i in C?
  5. Pointer Arithmetic: ++*ptr or *ptr++?
  6. Pre increment vs Post increment in array
  7. Order of operations for pre-increment and post-increment in a function argument? [duplicate]
  8. Difference between pre- and postfix incrementation in C (++a and a++) [duplicate]
  9. Operator precedence and operator associativity rules in c++ [duplicate]
  10. Is there a performance difference between i++ and ++i in C++?
  11. Post-increment and Pre-increment concept?
  12. Incrementing in C++ – When to use x++ or ++x?
  13. Why does “++x || ++y && ++z” calculate “++x” first, even though operator “&&” has higher precedence than “||”
  14. Post-increment on a dereferenced pointer?
  15. Operator precedence (bitwise ‘&’ lower than ‘==’)
  16. What is the difference between pre-increment and post-increment in the cycle (for/while)?
  17. What is more efficient, i++ or ++i? [duplicate]
  18. Pre- & Post Increment in C#
  19. Precedence of && over || [duplicate]
  20. Multiple preincrement operations on a variable in C++(C ?)
  21. Array increment operator in C
  22. Java increment and assignment operator [duplicate]
  23. Post-increment within a self-assignment
  24. Errors using ternary operator in c
  25. Operator precedence table for the C programming language
  26. ++i or i++ in for loops ?? [duplicate]
  27. Is x += 1 more efficient than x = x + 1?
  28. Getting a stack overflow exception when declaring a large array
  29. “undefined reference to `pow'” even with math.h and the library link -lm [duplicate]
  30. When printf is an address of a variable, why use void*?

Leave a Comment