在main与struct中初始化char数组

Question

im attempting to initialize an array of chars

if I do it like this in main it works fine

char arr1[20] = "initial";
printf("%s", arr1);

but if I try to do it anywhere else such as in a struct, then try to use it in my main function like

struct foo 
{
    char arr1[20] = "initial";
}

int main(void)
{
     struct foo foobar;
     printf("%s", foobar.arr1);
}

or

struct foo 
{
    char arr1[20];
}

int main(void)
{
     struct foo foobar;
     foobar.arr1 = "initial";
     printf("%s", foobar.arr1);
}

I start getting errors. Why does one work and the other doesn't?

Answer 1

Try like this..

struct foo 
{
char arr1[20];
}

int main(void)
{
 struct foo foobar;
 strcpy(foobar.arr1,"initial");
 printf("%s", foobar.arr1);
}

Answer 2

You are mixing up a struct definition with initialization of a variable .

The struct definition says which types make up a struct and what their names are, eg:

struct foo 
{
    char arr1[20];
};

says that " struct foo is a type we've just defined that consists of an array[20] of char ". There are no actual variables of this type yet.

Then you can declare and initialize instances of this type, in a similar way to how you declare and initialize arr1 in your first example:

struct foo foobar = { "initial" };