C++ Tutorial Index

C++ Tutorial C++ History C++ Installation C++ First Program C++ cin and cout C++ Data type C++ Variable C++ operator C++ Keywords

C++ Control Statements

C++ If C++ Nested if C++ If-else C++ If-else-if C++ Switch C++ Break C++ Continue C++ Goto C++ For loop C++ While loop C++ Do while loop

C++ Functions

C++ Call by Value C++ Call by Reference C++ Recursion Function C++ Inline function C++ Friend function

C++ Arrays

Single dimension array Two dimension array

C++ Strings

C++ Strings

C++ Inheritance

C++ Inheritance Single level Inheritance Multilevel Inheritance Multiple Inheritance Hierarchical Inheritance Hybrid Inheritance

C++ Polymorphism

C++ Polymorphism C++ Overloading C++ Overriding C++ Virtual Function

C++ Pointers

C++ Pointers C++ this pointer

C++ Exception Handling

C++ Exception Handling

C++ Constructors

C++ Constructors Default Constructor Parameterize Constructor Copy constructor Constructor Overloading Destructor

C++ File Handling

C++ File Handling C++ Writing to file C++ Reading file C++ Close file

Miscellaneous

C Vs C++ C++ Comments C++ Data Abstraction C++ Identifier C++ Memory Management C++ Storage Classes C++ Void Pointer C++ Array To Function C++ Expressions C++ Features C++ Interfaces C++ Encapsulation std::min in C++ External merge sort in C++ Remove duplicates from sorted array in C++ Precision of floating point numbers Using these functions floor(), ceil(), trunc(), round() and setprecision() in C++ C++ References C++ Friend Functions C++ Mutable keyword Unary Operators in C++ Initialize Array of objects with parameterized constructors in C++ Differences between #define & const in C/C++ C++ Program to Implement Shell Sort C++ Program to Implement Merge Sort Storage Classes in C Vector resize() in C++ Passing by Reference Vs. Passing by the pointer in C++ Free vs delete() in C++ goto statement in C and C++ C++ program to read string using cin.getline() C++ String Concatenation Heap Sort in C++ Swap numbers in C++ Input Iterators in C++ Fibonacci Series in C++ C ++ Program: Alphabet Triangle and Number Triangle C++ Program: Matrix Multiplication C++ Program to Print Fibonacci Triangle Stack in C++ Maps in C++ Queue in C++ C++ Bitset C++ Algorithms Priority Queue in C++ C++ Multimap C++ Deque Function Pointer in C++ Sizeof() Operators in C++ C++ array of Pointers free() Vs delete in C Timsort Implementation Using C++ CPP Templates C++ Aggregation C++ Enumeration C++ Math Functions C++ Object Class C++ Queue Initialize Vector in C++ Vector in C++ C++ STL Components Function overloading in C++ C++ Maximum Index Problem C++ find missing in the second array C++ Program to find the product array puzzle C++ Program To Find Largest Subarray With 0 Sum C++ Program To Move All Zeros To The End Of The Array C++ Program to find the element that occurs once C++ Program to find the largest number formed from an array Constructor Vs Destructor C++ Namespaces C++ OOPs Concept C++ Static C++ Structs C++ Try-Catch C++ User Defined Exceptions C++ Virtual Destructor C++ vs C# Malloc() and new in C++ Palindrome Number Program in C++ Snake Code in C++ Splitting a string in C++ Structure Vs Class in C++ Virtual Function Vs Pure Virtual Function C++ Bidirectional Iterators C++ Forward Iterators C++ Iterators C++ Output Iterators C++ Range-based For Loop Converting string into integer in C++ LCM Program in C++ Type conversion in C++ Add two numbers using the function in C++ Advantage and disadvantage friend function C++ Armstrong Number Program in C++ ATM machine program in C++ using functions Binary to Decimal in C++ Bit Manipulation in C++ C++ Constructor C++ Dijkstra Algorithm Using the Priority Queue C++ int into String C++ Signal Handling Decimal to Binary in C++ Decimal to Hexadecimal in C++ Decimal to Octal in C++ Factorial Program in C++ Function in C++ Hexadecimal to Decimal in C++ Octal to Decimal in C++ Reverse a Number in C++ Structure Vs Class in C++ C++ Forward Iterators C++ Output Iterators C++ Prime number program Char Array to String in C++ Constructor Overloading in C++ Default arguments in C++ Different Ways to Compare Strings in C++ Dynamic Binding in C++ Program to convert infix to postfix expression in C++ SET Data Structure in C++ Upcasting and Downcasting in C++ Reverse an Array in C++ Fast Input and Output in C++ Delete Operator in C++ Copy elision in C++ C++ Date and Time C++ Bitwise XOR Operator Array of sets in C++ Binary Operator Overloading in C++ Binary Search in C++ Implementing the sets without C++ STL containers Scope Resolution Operator in C++ Smart pointers in C++ Types of polymorphism in C++ Exception Handling in C++ vs Java Const Keyword in C++ Type Casting in C++ Static keyword in C++ vs Java Inheritance in C++ vs Java How to concatenate two strings in C++ Programs to Print Pyramid Patterns in C++ swap() function in C++ Structure of C++ Program Stringstream in C++ and its applications rand() and srand() in C / C++ C++ Ternary Operator C++ Scope of Variables While Loop Examples in C++ Star pattern in C++ using For Loops For Loop Examples in C++ Do-While Loop Examples in C++ Top 5 IDEs for C++ That You Should Try Once Assertions in C/C++ C++ Convert Int to String Continue in C++ While loop Diamond Pattern in C++ using For Loop How to Reverse a String in C++ using Do-While Loop How to Reverse a String in C++ using For Loop How to Reverse a String in C++ using While Loop Infinite loop in C++ Loops in C++ Returning Multiple Values from a Function using Tuple and Pair in C++ wcscpy(), wcslen(), wcscmp() Functions in C++

C++ References

C++ References

An alias is a reference variable that is another name for a variable already in existence. If a relation is initialized with a variable, it is possible to use either the important variables or the relation name to refer to the variable.

References vs. Pointers

References are always confused with indicators, but there are three significant differences between references and indicators:-

  • You are not allowed to have NULL references. You must always be in a position to imagine that comparison is linked to a legitimate storage part.
  • Upon initialization of a reference to an entity, it could not be changed to refer to another object. At any instance of time points may be pointing to another thing.
  • When it is generated, a reference has to be initialized. Points should also be initialized.

Creating References in C++

Find a word for the variable as a label attached to the location in memory of the variable. Then you can think of a reference as a second label attached to that place of memory. Thus, either the original variable name or the reference can be used to access the contents of the variable. For example, suppose we have the example below:-

int k = 20;

We can declare variables of reference as follows for k.

int& s = k;

Read the & as a response in those declarations. Hence, read the first declaration as "s is an integer description configured to k and read the second statement as" s would be an optimized double definition to t." Take the following example with references on int and double:-

#include <iostream>
using namespace std;
int main () {
   // declare simple variables
   int    k;
   double t;
   // declare reference variables
   int&    s = k;
   double& a = t;
   k = 8;
   cout << "Value of k : " << k << endl;
   cout << "Value of k reference : " << s  << endl;
   t = 15.2;
   cout << "Value of t : " << t << endl;
   cout << "Value of t reference : " << a  << endl;
   return 0;
}

Output:

C++ References

Example no. 2:-

#include<iostream>

using namespace std;

int main()

{

  int y = 20;

  // ref is a reference to y.

  int& refr = y;

  // Value of y is now changed to 20

  refr = 40;

  cout << "y = " << y << endl ;

  // Value of y is now changed to 30

  y = 25;

  cout << "refr = " << refr << endl ;

  return 0;

}

Output:

C++ References

Applications

Modify the passed parameters in a function: When a function obtains a variable reference, it can change the data values. For example, inputs are switched using references in the following program.

#include<iostream>
using namespace std;
void swap (int& firstname, int& secondname)
{
    int temp = firstname;
    firstname = secondname;
    secondname = temp;
}
int main()
{
    int j = 4, k = 8;
    swap( j, k );
    cout << j << " " << k;
    return 0;
}

Output:

C++ References

Avoiding a copy of large structures: Picture a device that has a broad object to obtain. If we pass that without regard, a new copy of it will be created, which will cause CPU memory and time wastage. To stop this, we should use the references.

References are less powerful than pointers.

  • The reference to some other attribute may not be made later whenever a comparison is formed; it could not be repartitioned. Often this is achieved using pointers.
  • References are not NULL. Points are also rendered NULL to show they do not point to something important.
  • Upon declaration, a reference must be configured. There is no such restriction with pointers because of the limitations above, references in C++ cannot be used to enforce data structures such as Linked List, Tree. In Java, examples have no limitations above and can be used to implement all data structures. References being stronger in Java is the primary reason that Java does not need pointers.



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