which one is declaration and which one is definition?

Saturday, 28 July 2012 | Unknown at 02:48 |

We often get confused between declaration and definition. Don't worry. After this article, It will not happen again. Trust me.


Definition :-  only once and consumes memory.
Declaration :- can be multiple times and does not consume memory.
Or We can say :-

a definition is the special kind of declaration that fixes the storage for an object

For Example :-
#include<stdio.h>
#include<conio.h>
int x[2]; // definition, it consumes memory
void main()
 {
    clrscr();
    printf("Hello");
   extern int x[]; // declaration and hence doesn't consumes memory
    printf("hello");
    getch();


 }


Here in declaration, there is no need of even specifying the size. Because m/y is already allotted to it.