Question

I was using my structure like this. I don’t like to typedef as I have told it can hide errors.
However, I was looking at some sample code and I have seen structures declared like this. And this is the normal way I declare them.

struct person
{
     int age;
     char name[32];
};

using like this:

    struct person person_a;
    person_a.age = 20;
    etc.

However, I have seen structures declared like this:

struct 
{
     int age;
     char name[32];
}person;

and

struct _person
{
     int age;
     char name[32];
}person;

What is the difference between all these different techniques, and how would you decide when it is the best to use each particular one.

Many thanks for any suggestions,

Answer 1

This:

struct 
{
    int age;
    char name[32];
}person;

declares a variable person that is a struct. The struct has no name, but you still use the person variable the same way.

struct _person
{
    int age;
    char name[32];
}person;

This is identical to:

struct _person
{
    int age;
    char name[32];
};
struct _person person;

It declares a struct named _person and then makes a variable called person of type struct _person.