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3. Under st anding Pointe r
Definition :
Variable store the values. E.g. int i store 5.
Pointer is a variable which store address of another variable. E.g. j store address of i , so j is a pointer.
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4. Pointer Declaration <data type> * <pointer name> int * ptr
Syntax :
<data type> * <pointer name>
Example :
int
* ptr
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5. Store Address to pointer
Syntax :
Pointer-name = & (variable name)
Example :
j = & i;
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6. Accessing Pointer * pointer-name *j Syntax : Example :
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7. Example : Pointer #include<stdio.h> #include<conio.h>
int main() {
int number =0; int *ptr;
printf(“\n Enter number”); scanf(“%d”, &number);
Output:
Enter number 5
5 is stored at 65524
ptr=&number; //assigning address of number to pointer ptr
printf(“\n %d is stored at %u ”, number , ptr);
// printing address using %u
getch();
return 0; }

8. Pointer With Function (call by reference)
#include<stdio.h>
int add (int * , int *);
//1. function declaration int * <--pointer
int main() {
int a=5 , b=6, y;
y=Add(&a , &b);
// 2. function call passing reference.
printf(“addition = %d” , y); return 0; }
int add (int * x, int * y) {
// 3. function definition
int result;
result= *x + *y;
// *x contain value 5
return result; }
Output:
addition =11

9. Pointer with Structure
Syntax:
Example:
struct struct-name
struct book { {
----
int price;
----
int pages;
----
char name[ 50 ]; }; };
struct struct-name * pointer-name ;
struct book * ptr1;
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10. Exam
ucture
Example

11. Array of Pointers arr[0] = & i ; arr[1] = & j; arr[2] = & k;
Definition :
The way there can be an array of ints or an array of floats, similarly there can be an array of pointers. Since a pointer variable always contains an address, an array of pointers would be nothing but a collection of addresses.
Example:
int * arr[4] ; arr is array of integer pointers. It contains 4 addresses of integer variables:
arr[0] = & i ;
arr[1] = & j; arr[2] = & k;
arr[3] = & l ;
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12. Pointe r To Pointe r int i , *j , **k ; int i =30 int *j = &i
Observe how the variables j and k have been declared,
int i ,
*j ,
**k ;
Here, i is an ordinary int, j is a pointer to an int (often called an integer pointer), whereas k is a
pointer to an integer pointer (often called a pointer to pointer).
variable
pointer
pointer to pointer
int i =30
int *j = &i
int **k = &j
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13. End of chapter