char array pointer & functions

[marianm]

Hello All,

I have following issue with pointer:

char *menu_pages[] = {
                        "Add",
                        "Edit",
                        "Remove",
                        "Back",
                        (char *)NULL,
}

int create_menu(char *choice[])
{
      int n_choices;
      n_choices = (sizeof(choice) / sizeof(choice[0]));

}

int main()
{
      create_menu(menu_pages);
}

n_choices = 1
what is wrong with this?


thankx for ur help
-mm-

[Galik]

That won't work because the parameter choice is a char** which is a different type to the array menu_pages. Taking sizeof() an array gives you the amount of memory the whole array occupies. But taking the sizeof() a char** only tells you how big a char** is, not all the data it points to.

The problem is that the declarations look the same. But they are not. With the variable menu_pages, it has a type array of char* and the compiler knows how big the data it contains is. But with your parameter choice the compiler has no idea how much data it points to.

[marianm]

Taking sizeof() an array gives you the amount of memory the whole array occupies.

- this is what I need also, because I alocating memory for array (size may change) and alocating working fine :)

Besides of this, I need know how much items are in the menu_pages, so i use

while(choice[i]) i++;

working fine for me :)

thanks

[firedraco]

Pass the size to the function.