why cant my printf pick up my user input? - c

Question

I have this
void main(int argnum, char** input)
{
int a=0, b=0, c=0, d=0, e=0, f=0, g=0, h=0, i=0, j=0, k=0, l=0, m=0, n=0, o=0, p=0;
printf("Enter the numbers from 1 to 16, in any order(separate by comma) : ");
scanf_s("%d" "%d" "%d" "%d" "%d" "%d" "%d" "%d" "%d" "%d" "%d" "%d" "%d" "%d" "%d" "%d", &a, &b, &c, &d, &e, &f, &g, &h, &i, &j, &k, &l, &m, &n, &o, &p);
printf("%d " "%d " "%d " "%d \n", a, b, c, d);
printf("%d " "%d " "%d " "%d \n", e, f, g, h);
printf("%d " "%d " "%d " "%d \n", i, j, k, l);
printf("%d " "%d " "%d " "%d \n", m, n, o, p);
}
my display is
a 0 0 0
0 0 0 0
0 0 0 0
0 0 0 0
for some reason my variables other than a, arent being caught.. whats wrong?

Answer 1

(separate by comma)
If you're separating the numbers with commas, the second and subsequent scans will fails, because there's no way to turn a comma into an integer.
Scanning for an %d integer will:
skip white space (which does not include commas); then
scan as many characters as needed to populate an integer, up until the first character that's not part of an integer.
If the first non-whitespace character is a comma, that's not suitable for an integer. Easiest solution is probably just to tell user to separate with spaces rather than commas.
Let's begin with a cut-down version that exhibits the same behaviour (and with single strings rather than those disparate ones):
#include <stdio.h>
int main(void) {
int a=0, b=0;
printf("Enter numbers from 1 to 2 in any order (separate by comma): ");
scanf("%d %d", &a, &b);
printf("%d %d\n", a, b);
}
Entering 1,2 for that gives you 1 0 as per your code. Entering 1 2 (space-separated rather than comma) gives you 1 2, which is what you're after.
Of course, if you need the commas, you can put that into the format string as well:
scanf("%d ,%d", &a, &b);
This will:
%d - skip optional whitespace and read integer;
<space>: skip whitespace before comma;
,: skip comma;
%d - skip optional whitespace and read integer.
Of course, it goes without saying that you should always check things that can fail, if that failure can affect you adversely:
if (scanf("%d %d", &a, &b) != 2) { // expect two things scanned
fprintf(stderr, "Something went horribly wrong!\n");
exit(1);
}

Answer 2

#include<stdio.h>
void main(int argnum, char** input)
{
int a=0, b=0, c=0, d=0, e=0, f=0, g=0, h=0, i=0, j=0, k=0, l=0, m=0, n=0, o=0, p=0;
printf("Enter the numbers from 1 to 16, in any order(separate by comma) : ");
scanf("%d" "%d" "%d" "%d" "%d" "%d" "%d" "%d" "%d" "%d" "%d" "%d" "%d" "%d" "%d" "%d", &a, &b, &c, &d, &e, &f, &g, &h, &i, &j, &k, &l, &m, &n, &o, &p);
printf("%d " "%d " "%d " "%d \n", a, b, c, d);
printf("%d " "%d " "%d " "%d \n", e, f, g, h);
printf("%d " "%d " "%d " "%d \n", i, j, k, l);
printf("%d " "%d " "%d " "%d \n", m, n, o, p);
}
after taking each value from the keyboard please press enter button it will work with this code