CODEWITHSUNDEEP
cmultidimensional-arraystrcpy
RubberLotus
RubberLotus

Reputation: 29

Why can't I strcpy?

For an assignment, I have to make a grade book in C consisting of several interlocking functions. I've gotten through the first few without (too many) headaches, but then there's this thing. Basically, I'm trying to take a character string and copy it into a two-dimensional array inside of a structure. I think I'm on the cusp of success, but the strcpy keeps throwing these two charming fellow in my face:

passing argument 1 of strcpy makes pointer from integer without a cast

expected 'char *restrict' but argument is of type 'char'.

Here's my code. gb is a pointer pointing to the structure. If I haven't clarified anything enough, please ask.

int add_assignment(Gradebook *gb, const char assgn[MAX_NUMBER_OF_ASSIGNMENTS]) {
  int i, j;

  for(i=0; i < MAX_NUMBER_OF_ASSIGNMENTS; i++) {
    for(j=0; j < (MAX_NAME_LEN+1); j++) {
      strcpy(gb->assignment_names[i][j], assgn);
    }
  }

  return 1;
}

Here is the Gradebook structure:

typedef struct gradebook {
  int number_of_students;
  Students students[MAX_NUMBER_OF_STUDENTS];
  int number_of_assignments;
  char assignment_names[MAX_NUMBER_OF_ASSIGNMENTS][MAX_NAME_LEN + 1];
  int scores[MAX_NUMBER_OF_STUDENTS][MAX_NUMBER_OF_ASSIGNMENTS];
} Gradebook;

Upvotes: 2

Views: 296

Answers (2)

owacoder
owacoder

Reputation: 4873

The problem is in the use of two loops:

for(i=0; i < MAX_NUMBER_OF_ASSIGNMENTS; i++) {
  for(j=0; j < (MAX_NAME_LEN+1); j++) {
   strcpy(gb->assignment_names[i][j], assgn);
  }
}

The inner loop is trying to copy a string (assgn) into a single char. You probably meant

for(i=0; i < MAX_NUMBER_OF_ASSIGNMENTS; i++) {
  strcpy(gb->assignment_names[i], assgn);
}

instead, but this may not be what you want either, where one assignment overwrites the entire list of assignments. It's hard to tell what logic you are looking for.

Upvotes: 2

Barmar
Barmar

Reputation: 781731

assignment_names[i][j] is a single character, not a string. assignment_names[i] is a character array, so you should copy to that. You don't need the inner loop.

int add_assignment(Gradebook *gb, const char assgn[]) {
    int i;

    for(i=0; i < MAX_NUMBER_OF_ASSIGNMENTS; i++) {
       strcpy(gb->assignment_names[i], assgn);
    }

    return 1;
}

Upvotes: 1

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