string literal in c

Question

Why is the following code illegal?

typedef struct{
   char a[6];
} point;

int main()
{
   point p;
   p.a = \"onetwo\";
}

Does it have any

Answer 1

As other answers have already pointed out, you can only initialise a character array with a string literal, you cannot assign a string literal to a character array. However, structs (even those that contain character arrays) are another kettle of fish.

I would not recommend doing this in an actual program, but this demonstrates that although arrays types cannot be assigned to, structs containing array types can be.

typedef struct
{
    char value[100];
} string;

int main()
{
    string a = {"hello"};
    a = (string){"another string!"}; // overwrite value with a new string
    puts(a.value);

    string b = {"a NEW string"};
    b = a; // override with the value of another "string" struct
    puts(b.value); // prints "another string!" again
}

So, in your original example, the following code should compile fine:

typedef struct{
    char a[6];
} point;

int main()
{
   point p;

   // note that only 5 characters + 1 for '\0' will fit in a char[6] array.
   p = (point){"onetw"};
}