C: Incompatible types in assignment error when trying to initialize char arrays within a structure

Question

I'm attempting to create a program for an assignment concerning structures. The idea is to create a structure containing variables for first and last name, phone number, and email address. I think most of my code is okay - perhaps rudimentary compared to modern coding standards for C, but it's where I'm at in the class.

Anyhow, I get a compiled error on the 5 lines attempting to initialize the email address fields saying incompatible types in assignment. I don't get those errors on the first or last name fields however, and I don't get why.

Any thoughts on why this is happening, or errors with the rest of the program are greatly appreciated! I can't really debug the rest of it myself until I get this compile error fixed, so I'm not sure what else is wrong yet.

#include <stdio.h>
#include <string.h>

/*****************************************
Structure declaration, creating type cont
*****************************************/

typedef struct contact {
  char fname[20];
  char lname[20];
  int number[10];
  char email[30];
} cont;

/*****************************************
Start of main function
*****************************************/
int main() {

int iMenu; //variable required for the menu
int iStorage; //variable used to store array entry chosen by the user
int iEntry1, iEntry2, iEntry3, iEntry4, iEntry5 = 0; //variables used for flagging assigned entries
/*******************************************
because of the typedef declaration, the struct command 
isn't necessary in creating an instance of the structure.
*******************************************/
cont myContact[4]; 

/*******************************************
we initialize the arrays contained within the structures
*******************************************/

  strcpy(myContact[0].fname, "\0");
  strcpy(myContact[0].lname, "\0");
  myContact[0].number = 0;
  strcpy(myContact[0].email, "\0");
  strcpy(myContact[1].fname, "\0");
  strcpy(myContact[1].lname, "\0");
  myContact[1].number = 0;
  strcpy(myContact[1].email, "\0");
  strcpy(myContact[2].fname, "\0");
  strcpy(myContact[2].lname, "\0");
  myContact[2].number = 0;
  strcpy(myContact[2].email, "\0");
  strcpy(myContact[3].fname, "\0");
  strcpy(myContact[3].lname, "\0");
  myContact[3].number = 0;
  strcpy(myContact[3].email, "\0");
  strcpy(myContact[4].fname, "\0");
  strcpy(myContact[4].lname, "\0");
  myContact[4].number = 0;
  strcpy(myContact[4].email, "\0");


/*****************************************
Creation of the menu to allow the users
to add entries or view them
*****************************************/
while (iMenu != 3) {
printf("Please select one of the following menu options: \n");
printf("\n1. Input new entries into the phonebook");
printf("\n2. View entries stored in the phonebook");
printf("\n3. Exit the Program\n");
scanf("%d", &iMenu);

/*******************************************
First menu option allows the selection of which
entry, and the storage of phonebook data
********************************************/
  if (iMenu == 1) {
    printf("Please input the entry in the phonebook you wish to change (0-4): \n");
    scanf("%d", iStorage);
    printf("Please input the first name of your new contact: \n");
    scanf("%s", myContact[iStorage].fname);
    printf("Please input the last name of your new contact: \n");
    scanf("%s", myContact[iStorage].lname);
    printf("Please input the phone number of your new contact: \n");
    scanf("%d", myContact[iStorage].number);
    printf("Please input the e-mail address of your new contact: \n");
    scanf("%s", myContact[iStorage].email);

    /**************************************
    Nested if statement sets the variable to
    flag if an entry has been made
    **************************************/
    if (iStorage == 0)
      iEntry1 = 1;
    else if (iStorage == 1)
      iEntry2 = 1;
    else if (iStorage == 2)
      iEntry3 = 1;
    else if (iStorage == 3)
      iEntry4 = 1;
    else if (iStorage == 4)
      iEntry5 = 1;
  }

  /***************************************
  Menu option 2 allows the user to display
  stored phonebook entries, using the iEntry
  variables as flags to determine which ones
  to display
  ***************************************/
  else if (iMenu == 2) {
    if (iEntry1 == 1)
      printf("%s %s phone number: %d e-mail address: %s", myContact[0].fname, myContact[0].lname, myContact[0].number, myContact[0].email);
    if (iEntry2 == 1)
      printf("%s %s phone number: %d e-mail address: %s", myContact[1].fname, myContact[1].lname, myContact[1].number, myContact[1].email);
    if (iEntry3 == 1)
      printf("%s %s phone number: %d e-mail address: %s", myContact[2].fname, myContact[2].lname, myContact[2].number, myContact[2].email);
    if (iEntry4 == 1)
      printf("%s %s phone number: %d e-mail address: %s", myContact[3].fname, myContact[3].lname, myContact[3].number, myContact[3].email);
    if (iEntry5 == 1)
      printf("%s %s phone number: %d e-mail address: %s", myContact[4].fname, myContact[4].lname, myContact[4].number, myContact[4].email);
  }
  else if (iMenu > 3) {
    printf("Invalid Entry.");
  }
}


return 0;
}

Answer 1

Your compiler almost certainly is complaining about these lines:

myContact[0].number = 0;
myContact[1].number = 0;
...

Not these:

strcpy(myContact[0].email, "\0");
strcpy(myContact[1].email, "\0");
...

struct contact declares its number field to be of type int[10], but you're trying to assign a single int to it.

Other unsolicited advice:

You could initialize your myContact array much more simply as:

cont myContact[4] = { { { 0 } } };

When you initialize part of an aggregate type (e.g. an array, a struct), the compiler will zero-initialize all of its remaining members automatically. For example, if you have:

char s[100] = "hello";

Then the first five bytes of s will be 'h', 'e', 'l', 'l', 'o', and each of the remaining 95 bytes will have the value 0.

int iEntry1, iEntry2, iEntry3, iEntry4, iEntry5 = 0;

This initializes only iEntry5 = 0. iEntry1 .. iEntry4 are left uninitialized, which probably is not what you intended.

When printing a prompt for input, you should call fflush(stdout) afterward.

Also, don't use scanf. It is error-prone and is hard to use correctly. You particularly need to be concerned with buffer overflows.

Answer 2

Each contact has ten numbers (int number[10], from 0 thru 9), and you are assigning as if it was a simple int number:

myContact[0].number = 0;

Also, don't do this: strcpy(myContact[0].fname, "\0");

You probably want "", not "\0", because there's always an implicit \0 at the end of a string.

(I hope fname and lname are there just as an exercise. Many people in the world have names that do not fit "first name - last name" paradigm)