C++ LANGUAGE POINTERS

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C++ LANGUAGE POINTERS

C++ POINTERS 

C++ pointers are easy and fun to learn. Some C++ tasks are 
performed more easily with pointers, and other C++ tasks, 
such as dynamic memory allocation, cannot be performed without them. 

As you know 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. 
Consider the following which will print the address of the variables defined: 

#include <iostream> 
 
using namespace std; 
 
int main () 
{ 
   int  var1; 
   char var2[10]; 
 
   cout << "Address of var1 variable: "; 
   cout << &var1 << endl; 
 
   cout << "Address of var2 variable: "; 
   cout << &var2 << endl; 
 
   return 0; 
} 

When the above code is compiled and executed, 
it produces the following result: 

Address of var1 variable: 0xbfebd5c0 


What are Pointers? 


A pointer is a variable whose value is the address of 
another variable. Like any variable or constant, you 
must declare a pointer before you can work with it. 
The general form of a pointer variable declaration is: 

type *var-name; 

Here, type is the pointer's base type; it must be a 
valid C++ type and var-name is the name of the pointer 
variable. The asterisk you used to declare a pointer is 
the same asterisk that you use for multiplication. However, 
in this statement the asterisk is being used to designate 
a variable as a pointer. Following are the valid pointer declaration: 

int    *ip;    // pointer to an integer 

double *dp;    // pointer to a double 

float  *fp;    // pointer to a float 

char   *ch     // pointer to character 

The actual data type of the value of all pointers, 
whether integer, float, character, or otherwise, is 
the same, a long hexadecimal number that represents 
a memory address. The only difference between pointers 
of different data types is the data type of the variable 
or constant that the pointer points to.