Pointers in C++

Pointers in C++ programming are used to point the locations in memory. A pointer is a variable whose value is the address of another variable, i.e., the direct address of the memory location.

Pointers

Pointers are aptly name: they 'point' to locations in memory. A pointer is a variable whose value is the address of another variable, i.e., direct address of the memory location. Like any variable or constant, you must declare a pointer before you can use it to store any variable address. 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++ data 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.

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.

Program Using Pointer

#include<iostream.h>
#include<conio.h>
void main()
{
 int x; //A normal integer.
    int *p; //A pointer to an integer, '*p' is an integer, so 'p'
            //must be a pointer to an integer.
    p = &x; //Read it, 'assign the address of 'x' to 'p'.
    cout<<"Enter any character to view address: ";
    cin>>x; //Put a value in 'x', we could also use 'p' here.
    cout<<"Address is: "<<*p; //Note the use of the '*' to get the value.
getch();
}

Program Working with Pointer

#include<iostream.h>
#include<conio.h>
void main()
{
   int var = 20; //actual variable declaration.
   int *ip; //pointer variable declaration.
   ip = &var; //store address of var in pointer variable.
   cout<<"Address of var variable: "<<&var<<endl;
              //address stored in pointer variable.
   cout<<"Address stored in ip variable: "<<ip<<endl;
              //access the value using the pointer.
   cout<<"Value of *ip variable: "<<*ip<<endl;
getch();
}