deleting all entries of a linked list in c, error

Question

So, im trying to delete all entries of the linked list in my phonebook lab, and it's reading an error that I don't know how to fix. The error is reading "incompatible types when assigning to type char[50] from type 'int.'

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
    
typedef struct phonebook{ 
    char first_name[70];
    char last_name[50];
    char phone_num[50];
    }entry; //TypeDef to modify structure name


    void addFriend(entry *, int *); //function prototype to add a friend 
    void dltFriend(entry *, int *, int);
    void showBook(entry *, int *);
    void alphaList(entry*, int*);
    void findNum(entry*, int*);
    void randSelect(entry*, int*);
    void dltAll(entry*,int*);

void dltAll(entry*phonebook, int*count){
int i;
for(i=0; i< *count; i++)
{

    do{
        phonebook[i].first_name = '\0';
        phonebook[i].last_name = '\0';
        phonebook[i].phone_num = '\0';
        break;
    }
    while (i <= *count);

}
printf("\nAll contacts deleted\n");
system("pause");
}

Answer 1

The error is reading "incompatible types when assigning to type char[50] from type 'int.'

The messages is due to this line:

phonebook[i].last_name = '\0';
\____________________/   \__/
 This is a char[50]       This is an integer

It makes no sense to assign an integer value to an array. If you want to turn last_name into an empty string do:

phonebook[i].last_name[0] = '\0';

Other notes:

A construct like:

do{
    ...
    break;
}
while (i <= *count);

makes no sense as the break will end the loop after executing ... once. So simply remove the loop.

Also I would expect the function to set *count to zero.

Answer 2

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

typedef struct phonebook{
    char first_name[70];
    char last_name[50];
    char phone_num[50];
    }entry; //TypeDef to modify structure name


    void addFriend(entry *, int *); //function prototype to add a friend
    void dltFriend(entry *, int *, int);
    void showBook(entry *, int *);
    void alphaList(entry*, int*);
    void findNum(entry*, int*);
    void randSelect(entry*, int*);
    void dltAll(entry*,int*);

void dltAll(entry*phonebook, int*count){
int i;
for(i=0; i< *count; i++)
{
        strcpy(phonebook[i].first_name,"NULL");
        strcpy(phonebook[i].last_name,"NULL");
        strcpy(phonebook[i].phone_num,"NULL");
}
printf("\nAll contacts deleted\n");
}
/*int main()
{
    void dltAll();
return 0;
}*/