How to initialize object of structure in main function?

Question

I am new to C programming and have a question. It's a simple programme but dont know why it gives such a compilation error.

#include<stdio.h>
#include<conio.h>
struct Book
{
 char book_name[20];
 char auther[20];
 int book_id;
};

void main()
{
struct Book b1;
clrscr();

 b1.book_name="c++"; 
 b1.auther="xyz";
 /* Above two line show compile time error Lvalue required */ 

 b1.book_id=1002;


printf("\n Book Name= %s",b1.book_name);
printf("\n Book Auther= %s",b1.auther);
printf("\n Book ID= %s",b1.book_id);


getch();
}

You can't assign arrays with `=` in C. Use `strcpy` and friends instead. — Eugene Sh., Jan 12 '17 at 16:01
But you can *initialize* a `char` array with a string constant. This problem (as posed) could be addressed by declaring `b1` with an initializer; `strcpy()` would not be needed in that case. — John Bollinger, Jan 12 '17 at 16:11

score 2 · Answer 1 · answered Jan 12 '17 at 16:02

C doesn't allow assignment from a string ("c++") to a char array (book_name). Instead, you'll need to copy the contents:

strcpy(b1.book_name, "c++");

Of course, this assumes that book_name is big enough to contain the contents. You can look into strncpy() to prevent overwriting your buffer once you get comfortable with the above.

How to initialize object of structure in main function?

1 Answers1