Am unable to get the second output printed?

ajiten · 06-16-2023, 07:14 AM

On Cygwin platform, on compiling C language program below, get the error, stated in comments, inside the program.

Code:

#include <stdio.h>
int main()
{
	int *pnum;
	char *pch;

	printf(" Size of integer pointer = %d\n\n", sizeof(pnum));
	printf("size of char pointer = %d", sizeof(pch));

	int x=10;
	int *ptr;
	ptr = &x;

	printf("\n \n ptr is: %i", x);

	int x1[6] = {1,2,3,4,5,6};
	
	ptr = x1;
        int i = 0;
	while (*ptr && i<=5) 
		printf("\nitem # %d ", i, "is :%d", *(ptr+i++));
                //Doubt: Only i is printed, while the value there is not printed on cygwin?
                //first tried with a similar expression:
                //printf("\n item # %d ", i, "is :%d", ptr[i++]);
                //that should yield the same result as above, as ptr[i++] is the same as *(ptr+i++)
}

The output is :

Code:

Size of integer pointer = 8

size of char pointer = 8

 ptr is: 10
 item # 1
 item # 2
 item # 3
 item # 4
 item # 5
 item # 6

But, it should be:

Code:

Size of integer pointer = 8

size of char pointer = 8

 ptr is: 10
 item # 1is :1
 item # 2is :2
 item # 3is :3
 item # 4is :4
 item # 5is :5
 item # 6is :6

ntubski · 06-16-2023, 07:44 AM

Quote:

Originally Posted by ajiten

Code:

		printf("\nitem # %d ", i, "is :%d", *(ptr+i++));

That's not how printf works, try

Code:

 printf("\nitem # %d is :%d", i, *(ptr + i++));

NevemTeve · 06-16-2023, 07:47 AM

You cannot invent new ways how `printf` should work, you have to use it in the documented way.

Code:

    printf("\n item # %d is :%d", i, ptr[i++]);

Also your code has some problems, but lets take them one by one.

digitechroshni · 06-29-2023, 11:56 AM

There are two issues:

The format specifier %d expects an integer argument, but "is :%d" is a string argument. To fix this, you need to separate the two format specifiers and provide two corresponding arguments. One for %d and another for the string.

The order of the arguments is incorrect. The value to be printed should come after the format specifiers.

Here's the corrected printf statement:

printf("\nitem # %d is :%d", i, *(ptr+i++));

This will properly print the item number (i) and the corresponding value (*(ptr+i++)).

I hope it would be helpful for you!