why x = x++ incorrect and only x++ is used for incrementing a variable?

general
1

see http://discuss.codechef.com/questions/56506/nov-cookoff-2014-brackets-solution-problem
this was where i got an error in nov cook off and wondered why it was giving an error in online compiler and not on codeblocks .

2

You do not need to ask “duplicate” question, you can ask in thread you referenced…

Good advice for a beginner is: “Do not use something, you do not understand fully”. And this is not related only to this operators…

According to my tests, it works on ideone (SDs3yR - Online C++ Compiler & Debugging Tool - Ideone.com ), which online compiler you meant?

As mentioned on SO, it’s undefined, so it may work in one compiler, but not in another…

3
  1. Undefined behaviour.
  2. If you are getting the result, that also depends on compiler. In different compiler, u will get different result.
  3. Reason: A variable cannot be modified more than once in any expression unless the modification is punctuated with a sequence point.
  4. Don’t try to operate more than once upon a variable in a single expression.
  5. There are 6 in Sequence points in standard C++. A sequence point guarantees that all the side effects of the previous expression are complete and no side effects from sub-sequence expression have been performed. Since i is modified more than once and read in this expression, the result is undefined.
4

It’s not incorrect.

5

thanks for the advice and help.

6

thanks for a good explanation.