C++ assignment operator associativity

Question

Possible Duplicate:
Undefined Behavior and Sequence Points

after the following c++ code, the array a contains: 0, 1, 2, 3, 4

int a[5] = {0,1,2,3,4};
int i = 2;
a[i++] = a[i++];

i expected it to be: 0, 1, 3, 3, 4

could anyone explain me why?

Well - what did you want to do with this? Or is it out of curiosity? — Martin Hennings, Jan 30 '12 at 14:45
http://stackoverflow.com/questions/4176328/undefined-behavior-and-sequence-points/ — Prasoon Saurav, Jan 30 '12 at 14:46

score 8 · Accepted Answer · edited May 23 '17 at 12:03

8

 a[i++] = a[i++];

Because it is Undefined Behavior.

edited May 23 '17 at 12:03

Community

answered Jan 30 '12 at 14:43

Alok Save

Do you have a link at hand from the specs? – Martin Hennings Jan 30 '12 at 14:45
@Martin: See the links inline.They have every Standard specification you might need. – Alok Save Jan 30 '12 at 14:49

1 Answers1