++i + ++i + ++i in Java vs C

int i=2;
i = ++i + ++i + ++i;

Which is more correct? Java's result of 12 or C = 13. Or if not a matter of correctness, please elaborate.

There is nothing like more correct. It is actually undefined and its called Sequence Point Error.

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The Java result makes sense to me because the operators give the result you would expect, but no serious program should contain a statement like this.

EDIT: I'm amused that this one sentence response has been my highest scored answer of the evening (compared to the dozen other answers I posted, some with pages of code samples). Such is life.

Java guarantees ([§15.7.1][1]) that it will be evaluated left-to-right, giving 12. Specifically, `++` has higher precedence that `+`. So it first binds those, then it associates the addition operations left to right

i = (((++i) + (++i)) + (++i));

§15.7.1 says the left operand is evaluated first, and [§15.7.2][2] says both operands are evaluated before the operation. So it evaluates like:

i = (((++i) + (++i)) + (++i));
i = ((3 + (++i)) + (++i)); // i = 3;
i = ((3 + 4) + (++i)); // i = 4;
i = (7 + (++i)); // i = 4;
i = (7 + 5); // i = 5;
i = 12;

In C, it is undefined behavior to modify a variable twice without a sequence point in between.

[1]:

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[2]:

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In C this is undefined behavior. There is no correct behavior.