C / C++ / MFC

int a=0;
int& b=a; // b is a new name for a
b=1;
cout<<a; // outputs 1

void f(int i)
{
  i=1;
}
 
int a=0;
f(a);
cout<<a; // outputs 0!

void f(int& i)
{
  i=1;
}
 
int a=0;
f(a);
cout<<a; // outputs 1

void foo(int *i);
 
...
 
// invocations of f have one of these two forms
 
f(something);
f(&something);

void foo(int& i);
 
...
 
f(*something);
f(something);

// version 1
int * p;
 
// version 2
int& p=... // it is mandatory that p be initialized, which may help preserve
// the sanity of the program

<br />
void FOO(int* p){*p+=1;}<br />
<br />
int* i = NULL;<br />
FOO(i)<br />