Question

structure may contain  
a) any other structure

b) any other structure expect themselves

c) any other structure except themselves and pointed to themselves

d) none of the above

Comments

You can't have same struct inside itself. So answer should be b) any other struct except themselves.

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Read the best answer of this link @suvasish pal..

https://stackoverflow.com/questions/14824563/struct-inside-of-same-struct-type

Answer 1

Answer is B.

A) Structures can definitely contain other structures. See chapter 6 in the book on C programming by Dennis Ritchie.

struct rect {
    struct point pt1;
    struct point pt2;
} ;

C) We can have structures which point to them, and we use these a lot when we create linked list. Example:-

struct Node
{
    int data;
    struct Node *next;
};

Here next is a pointer to structure Node.

B)But we cannot have structures which contain themselves. This will give you compile time errors. For example:-

struct regression {
   int int_member;
   struct regression self_member;
};

In order to compile a statement of this type, your computer would theoretically need an infinite amount of memory. In practice, however, you will simply receive an error message along the following lines:

 struct5.c: In function `main':
 struct5.c:8: field `self_member' has incomplete type

The compiler is telling you that self_member has been declared before its data type, regression has been fully declared -- naturally, since you're declaring self_member in the middle of declaring its own data type!

See this: https://stackoverflow.com/questions/588623/self-referential-struct-definition

and this: https://stackoverflow.com/questions/16741618/why-cant-a-struct-have-a-member-that-is-of-the-same-type-as-itself

this one too: http://www.asic-world.com/scripting/structs_c.html

Answer 2

Option B) is correct option structure cannot be used in itself...if we do so complation error will come instead we can use any other structure.....