How to initialize a struct in ANSI C?

Question

Hi guys!

I'm not a specialist for ANSI C (or regular C at all), so I stumbled about this stupid thing:

I want to initialize a struct element, splitted in declaration and initialization. This is what I got:

typedef struct MY_TYPE {
  boolean flag;
  short int value;
  double stuff;
} MY_TYPE;

void function(void) {
  MY_TYPE a;
  ...
  a = { true, 15, 0.123 }
}

Is this the way to declare and initialize a local variable of MY_TYPE in ANSI C? Or is there anything better or at least working.

I feel sorry to ask this. %-)

Update I ended up having a static initialization element where I set every subelement according to my needs.

Answer 1

As far as I can remember, this is not correct syntax even in C++. You can use the braces only in the declaration. Afterwards you should initialize it field by field.

Answer 2

void function(void) {
  MY_TYPE a;
  a.flag = true;
  a.value = 15;
  a.stuff = 0.123;
}

Answer 3

You've almost got it...

MY_TYPE a = { true,15,0.123 };

Quick search on 'struct initialize c' shows me this

Answer 4

a = (MYTYPE){ true, 15, 0.123 };

would do fine in C99

Answer 5

You can do it with a compound literal. According to that page, it works in C99 (which also counts as ANSI C).

Answer 6

malloc & memset or calloc

HTH

Answer 7

In (ANSI) C99, you can use designated initializer to initialize a structure:

MY_TYPE a = { .flag = true, .value = 123, .stuff = 0.456 };