Most of what you need to know about pointers..

pointers.cpp

// basic pointers demo

   int  data = 20;   // actual variable declaration.
   int  *ip;        // pointer variable 

   ip = &var;       // store address of data in pointer variable

  // prints an address
   cout << "Address stored in ip variable: ";
   cout << ip << endl; // prints out 8e34xA345te (An address)

   // access the value at the address available in pointer
   cout << "Value of *ip variable: ";
   cout << *ip << endl; // prints out 20... (The actual value)\

// array of pointers
MAX = 3;
int main () {
   int  data[MAX] = {10, 100, 200};
   int *pointer_to_data[MAX];
 
   for (int i = 0; i < MAX; i++) {
      pointer_to_data[i] = &data[i]; // assign the address of the three integers
   }
  
}

//POINTERS POINTING TO POINTERS
int main () {
   int  sample;
   int  *ptr_to_sample;
   int  **pptr_to_ptr;

   sample = 250;

   // take the address of var
   ptr_to_sample = &sample;

   // take the address of ptr_to_sample using address of operator &
   pptr_to_ptr = &ptr_to_sample;

   // take the value using pptr
   cout << "Value of sample :" << sample << endl; // prints 250
   cout << "Value of *ptr_to_sample :" << *ptr << endl; // prints out an address .. i.e (3e5XCde5)
   cout << "Value of **pptr :" << **pptr << endl; // prints out an address .. i.e (3e5XCde5)

   return 0;
}

// ARRAYS AND POINTERS
// HOW THEY CAN WORK TOGETHER
int main () {
  int MAX = 3;
   int  sample[MAX] = {10, 100, 200};
   int  *ptr;
 
   // let us have array address in pointer.
   ptr = sample;
	
   for (int i = 0; i < MAX; i++) {
      cout << "Address of sample[" << i << "] = ";
      cout << ptr << endl; // the address of sample will be printed
 
      cout << "Value of sample[" << i << "] = ";
      cout << *ptr << endl; // the value of sample will be printed
 
      // point to the next location
      ptr++;
   }
	
   return 0;
}