The compiler ignores increment operation

Question

Why compiler ignores increment operation? Version of gcc is 3.3. IDE: Eclipde

Program code:

// File t.cc
#include <stdio.h> 
int main (void)
{
  int x = 1;
  x++; // ? 
  printf ("x=%d\n", x);  
  return 0;
}

Running the program:

$ g++ -ansi t.cc
x=1

[Works for me](http://ideone.com/l1jnyj). Are you sure that's the code you're compiling? — Mike Seymour, Feb 20 '14 at 19:17
Check [here](http://ideone.com/HoaHQV) a copy paste of your code, how is that different from what you get? — Nikos Athanasiou, Feb 20 '14 at 19:24
What is the rationale for using the `-ansi` flag? Additionally, why use `printf()` instead of `cout` in a C++ program? Finally, the gcc you are using is 'ancient'. — pauluss86, Feb 20 '14 at 19:32
@dima, your problem is neither your code nor the compiler; it's most probably Eclipse. — pauluss86, Feb 20 '14 at 19:33
@dima try to clean your project , and then build it again. (in Eclipse IDE) it helps to solve problems from that kind. — Roma-MT, Feb 20 '14 at 19:34
[http://stackoverflow.com/questions/2518428/eclipse-how-do-i-refresh-an-entire-workspace-f5-doesnt-do-it][1] your eclipse project needs to be refresh. [1]: http://stackoverflow.com/questions/2518428/eclipse-how-do-i-refresh-an-entire-workspace-f5-doesnt-do-it — willll, Feb 20 '14 at 19:36
There are a couple of problems with this question. If you assume the compiler is at fault, posting the compiler version (and possibly the IDE you're using if it's relevant) is useful. Secondly, there's nothing wrong with the code sample. So one would naturally conclude that either your compiler installation is broken, or that whatever you're omitting from the question is at fault. **ECLIPSE IS NOT A COMPILER!** — , Feb 20 '14 at 19:38
To comment on the question-edit: the compiler is not ignoring anything. I suspect that (1) Eclipse is invoking `g++` by passing it some cached entry, (2) Eclipse is invoking `g++` with the correct code but executes a stale binary, (3) Both. Have you tried wiping your 'workspace' and installing 500 unrelated plugins? You should do the Eclipse dance until she is satisfied ;) — pauluss86, Feb 20 '14 at 19:44
Have you tried the command line version of `g++` instead of Eclipse? — Thomas Matthews, Feb 20 '14 at 20:45
@Thomas Matthews Yes, it's working. I think the problem is in Eclipse — Dima Kozyr, Feb 20 '14 at 20:48

score 10 · Answer 1 · answered Feb 20 '14 at 19:17

10

Your compiler is broken. A fix for this would be to get a new one.

answered Feb 20 '14 at 19:17

Luchian Grigore

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1

hahahaha dude come on – Nikos Athanasiou Feb 20 '14 at 19:18
1

@NikosAthanasiou it's a valid answer... – Luchian Grigore Feb 20 '14 at 19:19
Well the answer is correct , the code showed above in OP question should be compiled in any compiler as expected. – Roma-MT Feb 20 '14 at 19:19
3

More likely OP's not actually compiling the code in the question, but a subtly broken variant of it. – Feb 20 '14 at 19:21
2

indeed I have a feeling he trying this `printf ("x=%d\n", x++);` which will increment the `x` after the `printf`. – Roma-MT Feb 20 '14 at 19:22
@Roma-MT No, the code is correct – Dima Kozyr Feb 20 '14 at 19:22

Yuva Raj · Accepted Answer · 2014-02-20T19:33:55.363

3

Your code returns x value as 2. Re-compile & execute again.

enter image description here

edited Feb 20 '14 at 19:33

answered Feb 20 '14 at 19:26

Yuva Raj

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would suggests to clean then rebuild and run :) – Roma-MT Feb 20 '14 at 19:27
1

@Yuva, it's tagged as C++ and compiled by invoking `g++`. This, combined with the `.cc` extension suggests he is just mixing in C which shouldn't be a problem. – pauluss86 Feb 20 '14 at 19:35

The compiler ignores increment operation

2 Answers2