C Pointers Example

How to use pointers in c program?

'&' is used to get the address of the variable.

'*' is used to get the value at address.

Pointers Example:

#include<stdio.h>                                                             
                                                                                
void main()                                                                     
{                                                                               
  int val = 5;                                                                  
  printf("Address of val = %u\n", &val);                                      
  printf("Value of val = %d\n", val);                                           
  printf("Value of val using address = %d\n", *(&val));                         
}                                                            
                                                                                  

$ cc pointer1.c
$ ./a.out 
Address of val = 43479740
Value of val = 5
Value of val using address = 5

Define data type of value at address in variable

int *j;

Value at the address contained in j is an int data type.

Pointers Example:

#include<stdio.h>
                                                                                
void main()                                                                     
{                                                                               
  int i = 5;                                                                    
  int *j;                                                                       
  j = &i;                                                                       
                                                                                
  printf("Address of i = %u\n", &i);                                          
  printf("Value of i = %d\n", i);                                               
  printf("Address of j = %u\n", &j);                                            
  printf("Value of j = %d\n", j);                                               
  printf("Value of i = %d\n", *(&i));                                           
  printf("Value of i = %d\n", *j);                                              
}

$ cc pointer1.c
$ ./a.out 
Address of i = 4049270524
Value of i = 5
Address of j = 4049270512
Value of j = -245696772
Value of i = 5
Value of i = 5