Struct Initialization differnece-CodePudding

Given a struct in C defined as follows:

struct Person {
   const char *name;
   int age;
}

What are the differences between the two declarations below? I was confused when the struct keyword would precede the initialization below:

int main() {
   struct Person John = { .name = "John", .age = 10 };
      
   Person Jane = { .name = "Jane", .age = 10 };
   
   return 0;
}

CodePudding user response：

If you define the struct in this way:

struct Person {
   const char *name;
   int age;
}

Then (1) compiles while (2) does not, since the type of the struct is struct Person, not Person. "struct" is required.

// (1)
struct Person John = { .name = "John", .age = 10 };
// (2)
Person Jane = { .name = "Jane", .age = 10 };

However, if you use typedef:

typedef struct person_t {
   const char *name;
   int age;
} Person;

Then you can use both struct person_t and Person as the latter is an alias of the former.