How do I initialize a struct in C

I got a comment on how I initialize my struct in C, saying that It does not work and it does not compile either.

This is how I create and initialize a structure in C.

struct {
int a; 
int b;
char arr[3];
.
.
.
} data = {
.a = 1, 
.b = 2
};

main(){
/* do stuff */
}

This how I initialize my struct and It works and compiles. Yet I got a comment saying this would compile for c++ but not for C. Can someone ensure me that this correct alternative? If not why is it compiling with no errors?

>Solution :

I think there is a typo in the declaration of the data member arr. Instead of

char [3]arr;

you have to write

char arr[3];

You may not initialize an array with empty braces. So write for example

struct {
int a; 
char arr[3];
.
.
.
} data = {
.a = 1, 
.arr = { 0 }
};

In fact it is enough to write

struct {
int a; 
char arr[3];
.
.
.
} data = {
.a = 1
};

The array implicitly will be initialized with zeroes.