• This concept is used in C++.
  • When we create a variable of any data type, we use single identifier to identify that variable.

Example:    int i;

  • In this case, i is an identifier from which we can access that variable.
  • If we want to assign some another name to that same identifier then we can use the reference variable concept from C++.
  • A reference variable are such a variable which are refering to already created datatypes.
  • A reference variables are the names given to the variable.
  • Entry of that another name is in the symbol table.
  • We can create a reference variable for any data type.
  • As said above reference variables are only another name, due to which memory is not allocated for a reference variable.
  • Reference variables are needs to be initialized at the time of declaration.
  • We cannot create array of a reference variables.
  • Multiple references to the single variable are allowed.
  • But same reference variable to multiple variables is not allowed.
  • A reference to a reference variable is allowed.
  • We cannot create array of a references, because a reference variable does not get any memory.
  • But we can create a reference to an array.

//

Example:.

int main()

{

int i=10;

int &f=i;

printf(“%d”,i);

printf(“%d”,f);

return 0;

}

//

int main()

{

int i=10;

int &f=i;

int &d=f;

int &s=d;

//

// Reference to reference variable

//

printf(“%d”,i); //10

printf(“%d”,f); //10

printf(“%d”,d); //10

printf(“%d”,s); //10

return 0;

}

//

int main()

{

int i=10;

int &f=i;

int &d=i;

int &s=i;

//

// Multiple reference to single a variable

//

printf(“%d”,i); //10

printf(“%d”,f); //10

printf(“%d”,d); //10

printf(“%d”,s); //10

return 0;

}

C++ Reference Variables

//

int main()

{

// Error

// One reference can not refer to different variables

//

int i=10;

int k=20;

int &f=i;

int &f=k;

return 0;

}

//

//

// We can create a reference variable as a member of a class

// Memory is allocated for it also iside the class

// It must be initialized using the initialization list

//

class demo

{

public:

int i;

int &j;

demo():j(i)

{

i=10;

}

};

int main()

{

demo d;

cout<<d.i;//10

d.j++;

cout<<d.i; //11

cout<<d.j; //11

cout<<sizeof(d); // 8

return 0;

}

//

int main()

{

//

// We can create a reference to an array

//

int a[4]={1,2,3,4};

int (&d)[4] = a;

cout<<a[0]; // 1

cout<<a[1]; // 2

cout<<a[2]; // 3

cout<<a[3]; // 4

cout<<d[0]; // 1

cout<<d[1]; // 2

cout<<d[2]; // 3

cout<<d[3]; // 4

return 0;

}

//

int main()

{

int i=90;

int k=90;

int l=45;

int &f=i;

int &d=k;

int &a=l;

// Error

// We can not create an array of a references

//

int &(c[4]) = {f,d,a};

return 0;

}

//

int main()

{

int i=90;

int k=80;

int l=45;

int &f=i;

int &d=k;

int &a=l;

//

// In this way we can create an array of a references

//

int (c[4]) = {f,d,a};

printf(“%d”,c[0]); // 90

printf(“%d”,c[1]); // 80

printf(“%d”,c[2]); // 45

return 0;

}

//

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Written by Sourabh Bhunje

Sourabh Bhunje, B.E. IT from Pune University. Currently Working at Techliebe. Professional Skills: Programming - Software & Mobile, Web & Graphic Design, Localization, Content Writing, Sub-Titling etc. http://techliebe.com/about-us

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