Pointer:

Pointer is used to points the address of the value stored anywhere in the computer memory. To obtain the value stored at location is known as dereferencing pointer.

Pointer arithmetic:-

4 arithmetic operators that can be used în pointers :++, -, +=

Array of pointers:-

You can define array of to hold a number of pointers.

Pointer to pointer :-

C allows you to have pointer on a pointer and so on.

a → 10 → value 2000 => address

b → __ 3000

b=&a → _ 3000 _ 2000 [b points 4]

Program Pointer →

        int main (){
            int a = 5;
            int *b;
            b=&a;
            printf ("value of a =%d \n", a);
            printf("value of a = %d \n",*(&a));
            printf("value of a = "%d \n", *b);
            printf("address of a = %u \n", &a);
            printf("address of a = "%d \n", b);
            printf("address of b = % u\n", &b);
            printf("value of b = address of a = %u, b);
            return 0;
        }
        
OUTPUT:
            value of a = 5
            value of a = 5
            address of a = 3010494292 
            address of a = -1284473004
            address of b = 3010494296 
            value of b= address of a = 3010494292.
           

Program Pointer to pointer :-

            int main (){
            int a = 5; 
            int *b;
            int **c;
            b = &a;
            c = &b;
            printf ("value of a = %d\n", a);
            printf ("value of b = address of a = %u \n", b);
            printf ("value of c = address of b = %u \n", c);
            printf("address of b = %u \n", c);
            printf("address of c = %u \n", &c);
            return 0;
            }
            

OUTPUT:

            value of a = 5
            value of b = address of a = 28316.85116
            value of c = address of b = 2831085120
            address of b = 2831585120
            address of c = 2831685128
            

Structure :-

A structure is a composite data type that defines a grouped list of variables that are to be placed under one name in block of memory.

Program:-

Structure →

            struct structure - name.
            {
            data-type member 1;
            data-type member 2;
            .
            .
            .
            data-type member ;
            };
          

Advantages of structure :

1. It can hold vanables of different data types.

2. We can create objects containing different types of attributes.

3. It allows us to re-use the electer layout across programs.

4. It is used to implement other data structure like linked list, queues, trees and graphs.

Program :-

how to use structure in program →

            void main(){
            struct employee
            {
            int id;
            float salary;
            int mobile;
            };
            struct employee e1,e2,e3;
            printf("\n Enter ids, salary & mobile. no \n");
            scanf("%d %f %d", &e1.id, &e1.salary, &e1.mobile);
            scanf("%d %f %d", &e2.id, &e2.salary, &e2.mobile);
            scanf("%d %f %d", &e3.id, &e3.salary, &e3.mobile);
            printf("\n Entered result ");
            printf("\n %d %f %d", e1.id, el.salary, el.mobile);
            printf("\n %d %f %d", e2.id, e2.salary, e2.mobile);
            printf("\n %d %f %d", e3.id, e3.salary, e3.mobile);
        }
    

OUTPUT:

guess the output And write it here...