Thread: Incrementation in conditionals

Hi guys

My program does (or at least should do) the following: The user enters a sentence 19 characters long, or shorter. This string is saved in str.

Code:

#include <stdio.h>
#include <conio.h>

#define length 5

void main()
{
	int i=0;
	char str[length];
	
	
	while(((i++) < length-1) && (str[i-1]=getche())!=13)
	{
	}
	str[i-1]='\0';
}

My question is: When I use the incrementation-operator ++ in the condition of the while, then in the second condition, (str[i-1]=getche())!=13, is the original value of i used or is the incremented value used?

Best,
Niles.

Originally Posted by Salem

Question 3.8
&& is a sequence point, so the ++ always happens before the right hand expression is evaluated (if it's evaluated at all).

If you're confused, then just re-write the code so that it is clearer to you.
Say

Code:

while(((i) < length-1) && (str[i]=getche())!=13) {
  i++;
}

Oh, and drop the void main, and use of conio.h

Thanks. I will do as you said.

Best,
Niles.