fopen

where should i save my data2.txt file so Xcode can open it.

i dont know why Xcode tells me the program is fine but in quincy 2005 i get errors

this program has to get 50 integers numbers and then put in two arrays and each array 25 integer and then compare the two arrays

Code:

#include<stdio.h>

/* This function returns 0 (TRUE) when two integers are equal
 and it returns -1 (FALSE) when they are not equal*/
int comparason_function(int x1, int x2)
{
    if(x1==x2)
        return 0; // RETURN TRUE
    else if(x1!=x2)
        return -1; // RETURN FALSE
    return 0;
}

int main()
{
    FILE* file;
    char* filename;
    int ii;
    int jj;
    
    int array1[25];
    int array2[25];
    
    filename = "data2.txt";
    file = fopen (filename, "r");
    
    printf("THIS PROGRAM IS DONE BY REZA MOLOUDI. ALL RIGHTS ARE RESEVED\n");
    
    
    /* SAVE ALL the first 25 integers in array1*/
    for (jj=0; jj<25 ; jj++)
    {
        fscanf (file, "%d", &array1[jj]);
        //a[j] = i;
    }
    
    
    /* SAVE ALL THE SECOND 25 INTEGERS IN array2*/
    for (jj=0; jj<25 ; jj++)
    {
        fscanf (file, "%d", &array2[jj]);
    }
    
    /* BY CALLING THE comparision_function we figure out which intergers at which places are
     equal*/
    
    for(ii=0 ; ii<25 ; ii++)
    {
        if (comparason_function(array1[ii],array2[ii])==0)
            printf("A %d is found in Cell #%d \n", array1[ii], ii);
    }
    
    
    return 0;
}

The way your code is written, it requires the .txt file to be in the same folder as your workspace.

Where you get the errors i guess that your program can not simply find the file, so variable file is NULL.

Actually it is a good style, to always check if the filepointer returned by fopen is different to NULL. It might be NULL, if (for example) the file does not exist, if you do not have enough permissions on the file etc. .
It is the same way of thinking when you always check if malloc returns NULL to you

these are the errors i get

Try to convert all your comments with double slashes to the traditional ones with asterisks.
I mean replace this

Code:

// a comment

to this

Code:

/* a comment */

my problem is this line

Code:

//a[j] = i;

We put it like

Code:

/* a[j] = i; */

and still had problem?Post the errors compiler says and i suggest you to post the new code rather update the old posts