How to initialize a struct in accordance with C programming language standards

c struct initialization
cringe picture cringe · Dec 1, 2008 · Viewed 829.1k times · Source

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

typedef struct MY_TYPE {
  bool 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 accordance with C programming language standards (C89, C90, C99, C11, etc.)? Or is there anything better or at least working?

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

Answer

philant picture philant · Dec 1, 2008

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

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

Edit: Other members are initialized as zero: "Omitted field members are implicitly initialized the same as objects that have static storage duration." (https://gcc.gnu.org/onlinedocs/gcc/Designated-Inits.html)

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