File input/output query

mickomack

I am having a bit of difficulty with this question.Any help would be great thanks

#include <stdio.h>
void main(void)
{
FILE *fptr1, *fptr2;
int inp;
fptr1 = fopen(“input.dat”, “r”);
fptr2 = fopen(“output.dat”, “w”);
while (fscanf(fptr1, “%d”, &inp)==1){
if (inp >= 1 && inp <= 5){
fprintf(fptr2, “%d,”, inp);
}
}
fclose(fptr1);
fclose(fptr2);
}
(i) Suppose the file input.dat contains the following data:
0
2
-4
6
-1
5
Complete this sentence:
After executing this program, the file output.dat contains ______________ .
(ii) Re-write the above program so that it writes all the even values in a file called
input2.dat to a file called output2.dat


in reference to part(ii) could someone tell me how I'd go about rewriting the program so it would take in odd values.Is this the correct procedure

#include <stdio.h>
void main(void)
{
FILE *fptr1, *fptr2;
int inp;
fptr1 = fopen("input2.dat", "r");
fptr2 = fopen("output2.dat", "w");
while (fscanf(fptr1, "%d", &inp)==1){
if ((inp%2)!=0){
fprintf(fptr2, "%d,", inp);
}
}
fclose(fptr1);
fclose(fptr2);
}
I'm unsure whether this right or not and I can't seem to install a c compiler on my PC for some reason it would let me.

Mutant_Fruit

The modulus operator returns the remainder when you divide the number 'a' by 'b'. So you're perfectly right with your usage of it. Another way of writing it would be:

if(inp%2 == 1) //i.e. remainder IS 1.

EDIT: Whoops, misinterpreted the problem... First put [ CODE ] tags around your code, it makes it more readable. Then, write a comment beside each line of code telling us what you think it's doing. It should be obvious enough what is happening once you do that.

Cake Fiend

Looks good, you could even shorten it by just using:

if (inp%2)

Remember kids, if it's easy to read, it's not real C code!

Mutant_Fruit wrote:

if(inp%2 == 1) //i.e. remainder IS 1

Only problem with that is that it won't pick up negative numbers.