Difference between C++ pointer and reference

Hello,


Pointer is a variable which is taking memory reference of the other variable. It will not store direct value of any variable instead it will store memory address of the particular variable.

Reference is taking address of memory storage of particular variable.

int *p; -- here, p is a pointer variable.

int c = 5; -- here, c is a normal variable.

p = &c; -- here, p is taking memory reference of c.

print("%d",&p); --here, it will display memory address of c;

Also, please find below important links -

http://cplus.about.com/od/learningc/ss/pointers_9.htm[^]

http://www.cplusplus.com/doc/tutorial/pointers/[^]

http://augustcouncil.com/~tgibson/tutorial/ptr.html[^]


Hope, this will clear your doubt.

Regards,

Nilesh Shah.

As CPallini said, for the actual implementation, the compiler substitutes a reference with a pointer.
This is only a syntax thing.
You can see this if you take the assembly output of a program.

Here is a link where the man himself speaks about why references were added to C++ - Why does C++ have both pointers and references?[^]

A C++ reference is a const pointer with some added syntactic sugar.

try this sample code:

#include <iostream>
using namespace std;
void byval(int x)
{
  x += 5;
}
void byref(int & x)
{
  x += 5;
}
void bypointer(int * px)
{
  *px +=5;
  px++;
  *px +=5;
}
void main()
{
  int a[2];
  char c;
  a[0] = 0; a[1]=1000;
  byval(a[0]);
  byval(a[1]);
  cout << "byval " << a[0] << ", " << a[1] << endl;
  a[0] = 0; a[1]=1000;
  byref(a[0]);
  byref(a[1]);
  cout << "byref " << a[0] << ", " << a[1] << endl;
  a[0] = 0; a[1]=1000;
  bypointer(&a[0]);
  cout << "bypointer " << a[0] << ", " << a[1] << endl;
  cin >> c;
}