When declaring these two struct, what are their differences? Do the fields change from where they can be invoked?
Struct general:
typedef struct Etapa{
int h, m, s;
}Etapa;
Etapa etapas[3];
Etapa *puntero_etapa = etapas;
Struct anonymous:
typedef struct{
int h, m, s;
}Etapa;
Etapa etapas[3];
Etapa *puntero_etapa = etapas;
The second case is not an incomplete struct but, as you indicate later, anonymous.
The only difference between both is that the second can only be created using the alias:
Etapa variable;
struct /* ¿Que ponemos aqui? */ variable2; // <-- no compila
While in the first case you can create the structure using its name or alias:
Etapa variable;
struct Etapa variable;
Any advantages of having structures with a name?
The only one that occurs to me is that if a structure has no name you can not declare pointers to it within the structure itself ... something necessary to create linked lists ...
struct Nodo
{
struct Nodo* sig;
};
Of course, the alias does not need to be declared at the same time as the structure is declared ... it is usually more readable to declare it in an independent line:
struct Etapa
{
// ...
};
typedef struct Etapa Etapa;