A pointer is a variable that stores the memory address of another variable. Pointers allow indirect access to the data in memory. Pointer variables must be declared with a data type followed by an asterisk. This indicates they will store addresses. The ampersand (&) operator returns the address of its operand. The asterisk (*) operator accesses the value at the address stored in a pointer. Pointers can be assigned, compared, converted between types, and used in pointer arithmetic. Arrays of pointers store addresses, allowing a collection of memory locations to be accessed indirectly. A double pointer is a pointer variable that stores the address of another pointer.

1. Chapter-7 Pointers

3. Pointers Variable in memory 1000 1001 1002 1003 1004 1005 1006 103 Memory address

5. The ‘&’ and ‘*’ 3 ab 1000 Location name Value at Location Address

10. Write a program that computes the area and perimeter of a rectangle: #include <stdio.h> void rectangle(int a, int b, int * area, int * perim); int main() { int x, y; int area, perim; printf(&quot;Enter two values separated by space: &quot; ); scanf(&quot;%d %d&quot;, &x, &y); rectangle(x, y, &area, &perim); printf(&quot;Area is %d Perimeter is %d&quot;, area, perim); return 0; } void rectangle(int a,int b,int * area,int * perim) { *area = a * b; *perim = 2 * (a + b); }

21. Arrays of Pointers 1000 2500 2000 1500 i 5 10 j 20 15 l k 2500 2000 1500 1000 arr[0] arr[3] arr[2] arr[1] 1200 2700 2200 1700

23. Double Pointers 3 i 1000 1000 2000 j 2000 3000 k

25. Double Pointer OUTPUT: Address of i is 1000 1000 1000 Address of j is 2000 2000 Address of k is 3000 Value of i is 3 3 3 3 Value of j is 1000 Value of k is 2000