I'm confused by declarations. I'm trying to dynamically create an array of pointers to classes. so:


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

class emails
{
public:
    emails(){};
    emails(char *FName, char *LName, char *EMail, int ID){
	    strcpy(fname, FName);
	    strcpy(lname, LName);
	    strcpy(email , EMail);
	    id = ID;
    };

	char * GetName() const { return strcat(fname,lname);};
	void SetName(char * Fname, char *Lname){
	    strcpy(fname, Fname);
	    strcpy(lname, Lname);
	}
	char * GetEmail() const { return email;};
	void SetEmail( char * EMail) { strcpy(email,EMail);};

private:

	char fname[50];
	char lname[50];
    char email[50];
	int id;
};


void main(int argc, char *argv[])

{
   {
    /* Print a prompt prior to exiting so that you can view output */
    emails *local_emails[];
// I read this as: local_mails is an array of pointers to emails...however... the compiler tells me size of array is not known...ok so
    emails **local_emails;

//it doesn't like this either...can I do something like this in C++????

    local_emails = new emails[10];

    printf("Press a character....\n");
    getch();
   }
}

Michael Comperchio wrote:

>     {
>      /* Print a prompt prior to exiting so that you can view output */
>      emails *local_emails[];
> // I read this as: local_mails is an array of pointers to
> emails...however... the compiler tells me size of array is not
> known...ok so
>      emails **local_emails;

Ok, than:
    const int         LOCAL_EMAILS  = 10;
    local_emails    = new  ( emails * ) [ LOCAL_EMAILS ];

    for ( int  i = 0 ; i < LOCAL_EMAILS ; i++ )
        *( local_emails + i ) = new  emails ();

> //it doesn't like this either...can I do something like this in C++????

    emails       *local_emails;        // This should do for new  emails [
10 ];

>
>      local_emails = new emails[10];
>
>      printf("Press a character....\n");
>      getch();
>     }
> }

Jan Knepper wrote:
> Michael Comperchio wrote:
> 
> 
>>    {
>>     /* Print a prompt prior to exiting so that you can view output */
>>     emails *local_emails[];
>>// I read this as: local_mails is an array of pointers to
>>emails...however... the compiler tells me size of array is not
>>known...ok so
>>     emails **local_emails;
> 
> 
> Ok, than:
>     const int         LOCAL_EMAILS  = 10;
>     local_emails    = new  ( emails * ) [ LOCAL_EMAILS ];
> 
>     for ( int  i = 0 ; i < LOCAL_EMAILS ; i++ )
>         *( local_emails + i ) = new  emails ();
> 
> 
>>//it doesn't like this either...can I do something like this in C++????
> 
> 
>     emails       *local_emails;        // This should do for new  emails [
> 10 ];
> 
> 
>>     local_emails = new emails[10];
>>
>>     printf("Press a character....\n");
>>     getch();
>>    }
>>}
> 
> 

the actual number of emails is not known until runtime (the number of rows returned from a DB call)...but that's seems to be ok as this works...

emails **local_email;
....

local_email = new (emails * [res.size() * sizeof(emails *)]);
the key was (emails *...) I was stuck in my stubborn way on using ...new emails[res.size() * sizeof(emails *)]

Michael Comperchio wrote:

> I'm confused by declarations. I'm trying to dynamically create an array of pointers to classes. so:

..............code snipped..............

Since you are using C code, you could use function malloc.

You need to watch the char arrays. The way you are copying to them is very dangerous.

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

class emails
{
public:
    emails(){};
    emails(char *FName, char *LName, char *EMail, int ID){
        strcpy(fname, FName);
        strcpy(lname, LName);
        strcpy(email , EMail);
        id = ID;
    };

    char * GetName()  { return strcat(fname,lname);};
    void SetName(char * Fname, char *Lname){
        strncpy(fname, Fname,48);
        fname[48]='\0';
        strcat(fname," ");
        strncpy(lname, Lname,49);
        lname[49]='\0';
    }
    char * GetEmail()  { return email;};
    void SetEmail( char * EMail) {
		 strncpy(email,EMail,49);
	     email[49]='\0';
	};

private:

    char fname[100];
    char lname[50];
    char email[50];
    int id;
};


void main(int argc, char *argv[])   {
   emails *local_emails;

   if((local_emails=(emails *)malloc(10*sizeof(emails)))==NULL)
      exit(EXIT_FAILURE);

   int i;
   for(i = 0;i <10;i++)
      local_emails[i].SetName("George","Washington");
   for(i = 0;i <10;i++)
      printf("local_emails[%i] name: %s\n",
              i,local_emails[i].GetName());
   free(local_emails);
   printf("\nDa size of emails * = %u\n"
          "Da size of emails = %u\n\n",sizeof(emails *),
                       sizeof(emails));
   printf("Da End....\n");
   }