C99 struct initialization (C99/gcc)

[jilerner]

Question about C99/gcc struct initialization:

void ffoo(void) {
struct FOO { int a,b,c; };
struct foo = { .b = 22 };

What happens now to foo.a and foo.c ? Are they initialized to 0,
or left unitialized ?

Y.L.

 

[Emmanuel Delahaye]

(e-mail address removed) a écrit :

Question about C99/gcc struct initialization:

void ffoo(void) {
struct FOO { int a,b,c; };
struct foo = { .b = 22 };

Handy, isn't it ?

What happens now to foo.a and foo.c ? Are they initialized to 0,
Yes.

or left unitialized ?

No.

 

[Abhishek]

Thats one good thing you get with C99.

 

[Chris Torek]

(I saved this to reply to later, in case no one else did. I saw
no useful replies, so here is one.)

Question about C99/gcc struct initialization:

void ffoo(void) {
struct FOO { int a,b,c; };
struct foo = { .b = 22 };

This is a syntax error. Presumably you mean:

struct FOO foo = { .b = 22 };

What happens now to foo.a and foo.c ? Are they initialized to 0,
or left unitialized ?

In C99, unmentioned members of an otherwise-initialized aggregate
are initialized to zero. So foo.a and foo.c are set to 0.

What GNUC does with them is off-topic.