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Trouble filling a structure from a file...receiving error message incompatible types in assignment

Posted on 2004-12-01
Medium Priority
Last Modified: 2010-04-15
I am trying to fill the structure STUREC and am experiencing problems with my fscanf statement.  Upon compilation I receive the following message: proj6.c:83: incompatible types in assignment.  Can someone help me determine the source of my error?

My code is as follows:

//This program is designed to

#include <stdio.h>
#include <string.h>
#define STR_SIZE 25
#define ARR_SIZE 10
#define TRUE 1
#define FALSE 0

typedef struct
   char *month;
   int date;
   int year;

typedef struct
   char fName[STR_SIZE];
   char lName[STR_SIZE];
   int gradeLevel;
   char ssn[STR_SIZE];
   DATE birthDate;

typedef enum {false, true} BOOLEAN;

BOOLEAN openFile(int argc, char *argv[], FILE **fpIn);
int fillArray(FILE *fpIn, STUREC arr[]);
int getMonth(char *temp);
void sortArray(STUREC arr[], int numEls);
void swap(STUREC *stu1, STUREC *stu2);
void printArray(STUREC arr[], int numEls);
void closeFile(FILE *fpIn);

// do not change this function
int main(int argc, char *argv[])
   int numEls;
   FILE *fpIn;

   if (openFile(argc, argv, &fpIn))
      numEls = fillArray(fpIn, arr);
      printArray(arr, numEls);
      sortArray(arr, numEls);
      printArray(arr, numEls);

   return 0;

BOOLEAN openFile(int argc, char *argv[], FILE **fpIn)
   BOOLEAN success=false;
   if (argc >= 2)
      *fpIn = fopen(argv[1], "r");
      if (*fpIn != NULL)
         success = true;
         printf("\nERROR: Unable to open file for reading.\n");
      printf("\nERROR: Not enough command line arguments.\n\n");
   return success;

int fillArray (FILE *fpIn, STUREC arr [])
   int i;
   STUREC stu;
   for (i=0; i < ARR_SIZE; i++)
   arr [i] = fscanf (fpIn, "%s%s%d%s", stu.fName, stu.lName,
                     &stu.gradeLevel, stu.ssn);
Question by:csunnypl2
LVL 55

Accepted Solution

Jaime Olivares earned 200 total points
ID: 12721710
the problem is not fscanf
fscanf returns an integer representing the numbers of fields it has correctly parsed, in this case could be 4
You are trying to assign 4 to arr[i]
I guess you want to copy contents of 'stu' to arr[i], so correct code would be:

int fillArray (FILE *fpIn, STUREC arr [])
   int i;
   STUREC stu;
   for (i=0; i < ARR_SIZE; i++)
   fscanf (fpIn, "%s%s%d%s", stu.fName, stu.lName,  &stu.gradeLevel, stu.ssn);
   arr[i] = stu;
/* alternative to previous line:
   memcpy(&arr[i], &stu, sizeof(stu));


Expert Comment

ID: 12721742
Your problem's here:

arr [i] = fscanf (fpIn, "%s%s%d%s", stu.fName, stu.lName, &stu.gradeLevel, stu.ssn);

fscanf returns an int equal to the number of items it's read.  This line tries to assign that int value to an element in your STUREC array, arr.  This is what you want to do, I think:

fscanf (fpIn, "%s%s%d%s", arr[i].fName, arr[i].lName, &(arr[i].gradeLevel), arr[i].ssn);

And remove STUREC stu from your fillArray method (you don't use it anymore).


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