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post decriment in while

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Join Date: Oct 2006

Posts: 34

Reputation: pointers is an unknown quantity at this point

Solved Threads: 1

pointers

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post decriment in while

Oct 31st, 2006

I hav one doubt regarding post decriment,the code in c is as follows.............

void main()
{
clrscr();
while(i--!=6)
i=i+2;
printf("%d\n",i);
getch();
}

I know the output is 5, but i read in a book dat the post incriment or decrement operators are evaluated after reaching semicolon(

.....but in while condition,the ondition fails so it wont execute the next line so, directly reaches printf.Till now there is no semicolon still the i value is decresed......wts da reason...can u sugest me..?

Thanks & Regards.

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Join Date: Jun 2005

Posts: 275

Reputation: andor has a spectacular aura about

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andor

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Re: post decriment in while

Oct 31st, 2006

If you want help you must to fix your code. i is undefined and uninitialised. There are more problems with your code but first fix and beautify it.

If you want to win, you must not loose (Alan Ford)

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Join Date: May 2004

Posts: 178

Reputation: jim mcnamara is on a distinguished road

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jim mcnamara jim mcnamara is offline

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Re: post decriment in while

Oct 31st, 2006

Wow.

 Help with Code Tags 
 C Syntax (Toggle Plain Text) 
void main()  - don't use void main. main() returns an int.
{
  clrscr();
  while(i--!=6)      - where is i set to some intitial value?
      i=i+2;           - this is the end of the while loop 
                              I think you are missing {} to make a while block?
   printf("%d\n",i);
   getch();
}
 
void main()  - don't use void main. main() returns an int.
{
  clrscr();
  while(i--!=6)      - where is i set to some intitial value?
      i=i+2;           - this is the end of the while loop 
                              I think you are missing {} to make a while block?
   printf("%d\n",i);
   getch();
}

You do realize that your while loop subtracts then adds to the same variable, essentially in the same statement. Eeeek...

Back up.

What are you trying to do?