How to edit multiple variables inside a structure in C

Question

typedef struct
{
   string color;
   int age;
}Dog;


int main(void)
{
    Dog cookie = ("brown", 6);
    cookie.color = "blue";
    cookie.age = 12;
}

Hello, I'd like to know if there's a way to edit multiple structure values as such, while only using a single line instead of repeating "structName.varName" over and over.

Would there be a similar method for changing multiple values for objects in C as well? Thank you so much.

You *are* allowed to write two assignments on a single line, if that is the only requirement. :-) — BoP, Aug 09 '23 at 10:27

score 3 · Accepted Answer · answered Aug 09 '23 at 09:29

3

You can assign multiple struct members a value at once, by using a compound literal temporary object:

cookie = (Dog) { "blue", 12 };

Or for increased readability, combine this with designated initializers (equivalent code):

cookie = (Dog) { .color = "blue", .age = 12 };

answered Aug 09 '23 at 09:29

Lundin

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However, this will assign *all* struct members, not a strict subset of struct members. – Ian Abbott Aug 09 '23 at 09:43
@IanAbbott Not really stated as a requirement in the question. In order to preserve some members, you'd have to do something like: `cookie = (Dog) { .color = "blue", .age = 12, .fur = cookie.fur };`. I think this should be ok in terms of assignment operator sequencing. – Lundin Aug 09 '23 at 09:47
3

I just thought it was worth pointing out as a caution for the uninitiated who might assume it was only assigning the named members. – Ian Abbott Aug 09 '23 at 09:53
If that's a common operation I'd still prefer an appropriate setter function… Otherwise biting the bullet and do two manual assignments appears preferable to me as well. – Aconcagua Aug 09 '23 at 09:56

How to edit multiple variables inside a structure in C

1 Answers1