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Hence it is preceded by * . Variable p
also contains address, since p is also a
variable.
Contents of variable a can be accesed
by a or *p . *p means contents of the
memory of a.
Note :- * means contents of
& means address of
Address of operator :- & is called address
of operator. Any variable preceded lby &
indicates the address of memory location.
Ex:- int b ;
&b gives some address in whichcompiler allocates for a
variable b 1010.
Ex :- int a=5 ;
Int *p=&a ;
Printf(%d,a); gives output 5
Printf(%d,*p); gives output 5
Printf(%d,&a); gives output -42
Printf(%d,p); gives output -42
(address of a)
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Printf(%d,&p); gives output -40
(address of p)
Note :- address always takes unsigned
integer, thus pointer variable always tekes
2 bytes of memory inrrespective of its
data type.
Declaration of a double pointer :- double
pointer is same as similar to the pointer,
but it sotres address of another pointervariable.
Ex:- int a = 5 ;
int *p = &a ;
int **p = &p ;
where a is a variable whose content is 5
and contains some address as -42 , p is a
pointer variable which stores the address
of a also p contains some address as -40.
q is a double pointer variable which
stores the address of pointer variable alsoq contains some
address as -38.
Ex :-
/* Example Program */
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/* To print the value and address of
pointer variables and normal variables */
#include
#include
main()
{
int a=5,*p=&a,**q=&p;
clrscr();
printf("a=%d\n",a); /* gives output
5 */
printf("*p=%d\n",*p);/* gives output 5
*/
printf("&a=%d\n",&a); /* gives output
-42 */
printf("p=%d\n",p);/*gives output -42
(address of a) */
printf("&p=%d\n",&p);/*gives output-40(address of
p*/
printf("q=%d\n",q);/* gives output -40
(address of a) */
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printf("&q=%d\n",&q);/*gives output
-38(address of p)*/
printf("**q=%d\n",**q); /* gives output
5 */
getch();
}
