C++: Reference Variable:

C++:

Reference Variable:

Reference is an alias created for the variable.

Anallogy:Nickname

Important  example:

int  a=10;

  int &b=a;

  cout<<"value a="<<a;

  cout<<"value b="<<b; 

O/P:

Value a=10

Value b=10

& is a reference operator.syntax  int  &b=a; creatres another name b for the variable a.  i.e we can say b is a reference to a.

If we manipulate the value of b e.g b=10  then the value of a gets changed.

int a=10;

  int &b=a;

  b=20;

  cout<<"valu a"<<a;

  cout<<"valu b"<<b; 

o/p:

Value a=20

Value b=20

WHILE USING REFERENCE WE SHOULD KNOW……..

Reference have to be initialized

No memory is allocated to reference

Difference between pointer and reference

Pointer is flexible collaction

Reference is a rgid collection

Int *p=&I;

Int k;

P=&k;

A pointer has to be de-referenced before you can access the value at the addres contained in it. A reference is moreover a direct connection as it’s just another name for the same memory location.

We can have an arry of pointers whereas we can not have an aray of reference.

Const keyword

Constants should be initialized

Int i=10;

Const int*p=&I;

P=&k(correct)                                                                     (*p)++       incorrect

P++(correct)                                                                         *p=20 incorrect

Here,the pointer itself is not a constant and neither is the integer that it is pointing tp, a constant.we can change the address in the pointer by assigning some other address to it.but we cannot modify the contgents of the variable that it is pointing to,through that pointer.

Note:See some other cases like

1.pointer to a constant integer

2.contant pointer to an integer

3.constant pointer to a constant integer