C: In what cases, forward declaration of structure is preferred ?

Question

I know about the forward declaration of structure but don't know when it should be used or preferrable ? I can't envision the scenario.

Answer 1

if Structure Defination is some where else but you want to use the structure as a data member of other structure defination in this case Structure forward declaration is required.

Ex:
typedef struct abc NODE;

struct xyz
{
NODE *link; /*Here if forword declaration is not present then compiler will pop up the error */
};

typedef struct abc
{
int a;
int b;
}NODE; //Here NODE will represent as a struct abc