Could anyone explain why we can't assign string directly through = operator in structure concept in C programming

Answer 1

in the latest standard only int main() is allowed

Answer 2

A string in C is a char array and you can't assign to arrays.
Example:

// struct S { char str[11]; };
struct S s;
strcpy(s.str, "foo");

Beware strcpy may cause a buffer overflow...

Answer 3

Thank you so much. And why we are using always int main in structure ?. Can we use void type?