Simple C Code

general
21

Can you please check the answer in any non-gcc compiler like turbo c++ or dev cpp? I have only gcc and getting 16 as answer. My concept might be wrong.

22

Shouldn’t the incrementation work before evaluation of the expression making the value of x=6?

23

Same here. I’ll check though. I presume that doesn’t make any difference right!!

24

Some times, different compilers give different answers if compiler is not designed according to ISO/ANSI standards. But this should not be the case in gcc though.

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Please run the code in any compiler and check the output.

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printf("%d\n",++x + ++x + x++);
This will not print 18 but it prints 16.the explanation is :
ADDITION OPERATOR TAKES IN ONLY TWO INPUTS AT A TIME…
In the first case, there are only two operands and hence ans is 10.

But in the second case,there are 3 operands .now the operation is performed on the first two operands and the answer is stored in a temp register,this value is 10.For the second addition operation value stored in temp register and the new operand are added up.the new operand is ++x(which will be 6)(NOTE:performing ++x will not change temp value(10)) and hence answer is 10 +6=16.

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if there is another ++x then this 16 value(from the previous case) is stored in the temp register and the new operand ++x(which will now be’7’)is added with it and hence answer would be 16+7 =23.
if this is followed by another ++x ans would be 23+8=31 and so on.
i think this would help,if you still hve any doubt comment below…if you found my post helpful upvote and mark it as accepted answer…

28

the answer is 9 in turbo C

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29

what about ++x + ++x + ++x ???

30

in turbo c
?

31

++x + ++x + ++x in turbo C is 15 as expected ( 4 + 5 + 6)
and further more will be like this 4+5+6+7+8+9+10…

32

even in C# ++x + ++x is 9 in Visual Studio express

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33

@geeksoul Suprising! Thanks for the info that was helpful.

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34

Any idea which complier among Dev C++, Turbo C is designed according to ANSI standards?

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Neither, they have added lots of their own features. GCC is in accordance with the standard. I checked the answer on various compilers and got 16 as answer, but in turbo c, the answer was 15. Sorry for my wrong answer.

36

Yes, It is 15 in turbo c

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Thanks @sunny210 :slight_smile: I am happy that I could help you :slight_smile:

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@dragonemperor even in C# it is 15 but I am still not getting how could ++x + ++x is equal to 10? which compiler you are using?

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gcc compiler

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6 (Converted in 6 from 5) + 6 (still 6 but now converted in 7) + 8 (converted 7 to 8) + 9 (converted 8 to 9)