odd even number

[western46]

I'm supposed to make a program that reads off a txt file called integers.txt. It reads the numbers and tells the user "how many numbers you have entered, how many among them were even, and how many were odd. The program must also display the average of integer numbers that were odd." I wrote the code below. It runs but for some reason it keeps saying that I have zero numbers, zero even numbers, zero odd numbers etc. I don't know what's wrong. Can someone please help me out? Thanks.

#include <stdio.h>


int
main (void)
{
       int number, e, o, s, average;
    


    FILE *integers;


    integers = fopen ("integers.txt", "r");


    /*initialization*/
    e = 0;
    o = 0;


    /* read number by number until the end of file */
    while (fscanf (integers, "%d", &number) !=EOF) 
    {
    
     if (number%2 == 0)
          e = e + 1;
             
     else                   
         o = o + 1;            
    
    }     
    fclose (integers);
    /* final report */
    
    s = e + o;
    printf ("There are %d numbers in the file.\n", s);
    printf ("The total number of even numbers numbers is %d.\n", e);
    printf ("The sum of all the odd numbers numbers is %d.\n", o);
    average = o / e;
    printf("The average number of odd number is %d\n.", average);


        return (0);
}

[stahta01]

You never check if the file was opened successfully; it might give zero results if the file failed to open.
Check for "integers == NULL" and output a error message.

Tim S.

[western46]

hey when i put "integers == NULL" in my code, it gives me an error message. What's that suppose to mean?

I started tweaking the code to figure out what's wrong, i think for some reason the if and the while loops don't seem to be executing properly. Does anyone see anything wrong with it?

thanks for your help Tim.

[TheBigH]

It runs well for me (except for a logic error in line 40), so I suspect it's not opening the file correctly for you. Can you post the contents of integer.txt please?

[western46]

This is exactly how the numbers appear in integers.txt:
"2 2 8 8 4 2 5 3 9"

thanks for the help BigH.

[BillyTKid]

    while (fscanf (integers, "%d", &number) !=EOF) 
    {

This is known as newbie stuff, because it is a infinite loop if fscanf fails (e.g. a nondigit char occurs). (fscanf returns 0, and filepointer stops)

[western46]

How would you fix it?

[anduril462]

The scanf functions return the number of succesfully converted items. You ask for one each time (just one "%d"), so you keep looping while it returns 1.

[neveragn]

The scanf functions return the number of succesfully converted items. You ask for one each time (just one "%d"), so you keep looping while it returns 1.

I don't understand it. Can you please show it

[quzah]

Did you make a new account to say that? Why didn't you just use your normal one? Do you know how functions return values? Do you know how to compare values? Do you know How To Ask Questions The Smart Way?


Quzah.

[western46]

that wasn't me. It's probably another person from my class. I've found a new way to do this. So no need anyone to fix this. My new program works now. THANKS FOR EVERYONE'S HELP!!

[Dr.Tautology]

I am completely new to programming and I have a elementary question about how to test for an even number. I understand that ((n%2)==0) tests this because the number needs to be divisible by 2, but I don't understand why the boolean expression ==0 works, e.g 2%2 is not = to 0. I understand that == is a boolean expression, but the book I'm learning from explains it as still evaluating for equality, but provides either true or false as a value. What am I missing? I'm guessing that it has something to do with the remainder from the division being equal to 0, but I don't really understand why that would be? Could someone please explain this to me?

[failure67]

% is the modulo operator. It divides two operands and gives you the remainder. 2 divided by 2 is 1 with a remainder of 0. So 2%2 does equal 0.
Because 2%2 == 0, the statement would return true.

[iMalc]

Please do not hijack and reopen someone else's slightly old thread.
If you have a question of your own, start your own thread.