Interview Preparation topic : Pointers in C

What is a Pointer?

A pointer is a variable which contains the address in memory of another variable. Every variable is a memory location and every memory location has its address defined which can be accessed using ampersand (&) operator, which denotes an address in memory.

Lets Look at the following example:

1. include <stdio.h>

int main ()

{
  int  temp;
  int temp1;
  printf("Address of temp variable: %x\n", &temp );
  printf("Address of temp1 variable: %x\n", &temp1 );
  return 0;

}

When the following code is compiled and executed:

Address of temp variable: edf53400
Address of temp1 variable: adf9a5f6

To declare a pointer to a variable do:

type *pointer;

Where type can be int, double, float, char and pointer can be any variable.