Use Of Pointers In C language

Use Of Pointer In C Language:-
We Have already Discussed About Pointers In Previous Post.
This is the most important and useful IN C programming .
The Uses Of Pointers In C Language Is Given below:-
1.Array of pointers:-We Can Use Collection Of Pointer by using
  An Array Of Pointers.
2.Pointer to pointer:-C allows you to have pointer on a pointer.
3.Passing pointers to functions:- We Pass Pointer As  Arguments.
Now We Will know About These Uses Of Pointers One By One:-
1.Array of pointers:-
In This Method We Declare An array For Storing Pointers:
declaration of an array of pointers to an integer:-
int *ptr[MIN];
declaration of an array of pointers to an float:-
flot *ptr[MIN];
declaration of an array of pointers to a CHAR:-
char *ptr[];
Example Program:-
THIS PROGRAM DEMONSTRATES ARRAY OF POINTER,
WE SIMPLY PRINT ADDRESS AND VALUE OF POINTERS
#include <stdio.h>
const int MAX = 5;
int main ()
{
int *ptr;
int var[] = {10, 100, 200,400,500};
int i;
ptr=var;
for (i = 0; i < MAX; i++)
{
printf("Value of var[%d] = %d\n", i, var[i] );
printf("Adress Of var[%d]=%x\n",i,&var[i]);
}
return 0;
}
The Output Of Program Is:-
Value of var[0] = 10
Adress Of var[0]=7100cc50
Value of var[1] = 100
Adress Of var[1]=7100cc54
Value of var[2] = 200
Adress Of var[2]=7100cc58
Value of var[3] = 400
Adress Of var[3]=7100cc5c
Value of var[4] = 500
Adress Of var[4]=7100cc60
2.Pointer to pointer:-
*It is a form of multiple indirection, or a chain of pointers.
*When we define a pointer to a pointer, the first pointer contains
 the address of the second pointer which points to the location that
 contains the actual value.
Declaration of pointer to pointer:-
It must be declared by placing an additional asterisk in front of its name.
As For Example:-
int **ptr;
3.Passing pointers to functions in C:-
*For This simply declare the function parameter as a pointer type.
Example Program:-
IN this program we pass two pointers as an arguments,
#include <stdio.h>
/* function declaration */
void swaping(int *a, int *b); //passing pointers as an arguments
int main ()
{
/* local variable definition */
int x = 62;
int y = 52;
printf("Before swaping the value of x= %d\n",x);
printf("Before swaping the value of y= %d\n",y);
swaping(&x, &y);  // calling a function to swap the values.
              //("&x")indicates pointer to x i.e. address of variable x 
              //("&y")indicates pointer to y i.e. address of variable
return 0;
}
/* function definition to swap the values */
void swaping(int *a, int *b)
{
int temp;
temp = *a; /* save the value at address a */
*a = *b;   /* put b into a */
*b = temp; /* put temp into y */ 
printf("After swaping the value of x= %d\n",*a);
printf("After swaping the value of y= %d\n",*b); }
The Output Of This Program:-
Before swaping the value of x= 62
Before swaping the value of y= 52
After swaping the value of x= 52
After swaping the value of y= 62

                                               -:  Thanks A Lot :-
                                              -:  Please Share this:-