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++

Constructor Vs Destructor in C++

C++ Constructor

A function Object () { [native code] } is a member function that shares the same name as the class. It is called automatically whenever a class object is generated.

class Name  // syntax
{  
……….  
public  
Name ([parameter list])  
{  
……………….  
}  
};

Explanation:

The constructor's name is class name, the public specifier is an access specifier, and the parameter list is optional in the above syntax.

Example of a program showing the use of constructor in C++:

#include <iostream.h>  
#include <bits/stdc++.h>
#include <stdlib>
#include <conio.h>  
using namespace std;  
class First_hello {     // The class  
  public:           // Access specifier  
   first_hello () {     // Constructor  
      cout << "Hello World! Program in C++ showing the use of Constructor";  
    }  
   void display() {  
     cout <<"Hello World!" <<endl;  
   }  
};  
int main() {  
  hello myObje;   /  
  return 0;  
}  

OUTPUT:

Hello World!

Types of Constructor available in C++

  1. Default constructor
  2. Dynamic constructor
  3. Parameterized constructor
  4. Copy constructor

Default Constructor

A default function Object () { [native code] } is a function Object() { [native code] } that does not accept any parameters. If a class doesn't have a function Object () { [native code] }, the compiler constructs one for it implicitly.

class name {  //syntax
private:  
………..  
………..  
public:  
name ()  
{  
…….  
}  
} 

Explanation:

There are no arguments or parameter lists in this sort of function Object () { [native code] }. The compiler constructs the class's default function Object () { [native code] } if no function Object() { [native code] } is defined in the class.

Parameterized Constructor

A parameterized function Object() { [native code] } is a type of function Object() { [native code] } that can accept parameters. It's used to provide objects a separate set of values when they're created.

Class Name  //syntax
{  
…………;  
…………;  
Public:  
Class Name (parameter list)  
{  
………….;  
}  
};

Explanation:

The constructor's parameter list can be defined here.

Copy Constructor

A function Object () { [native code] } that is used to create a new object from an existing one. The copy function Object () { [native code] } is used to copy data from another object of the same type.

Class (Name, &object)  //syntax
{  
………….;  
………….;  
}  

Explanation:

The object in the above syntax refers to an item that is utilized to initialize another object.

Dynamic Constructor

This function Object () { [native code] } can be used to allocate memory for objects while they are being created. Dynamic initialization is the process of initializing the data members of an object after it has been created.

C++ Destructor

The same class name prefixed by the () tilde symbol is used for destructors. It removes and destroys the object's memory, which was allocated by the function Object () { [native code] } during its creation.

class Name  //syntax
{  
…………….;  
…………….;  
public:  
abc();            //constructor  
~abc();           //destructor  
};

Explanation:

In C++ programming, the tilde symbol is used to define the destructor. Because the Destructor takes no arguments and returns no value, it cannot be overloaded.

Example of a program showing the use of destructor in C++:

#include <iostream.h>  
#include <bits/sdtc++.h>
#include <stdlib>
#include <conio.h>  
using namespace std;  
class Helloworld {  
public:  
  //Constructor  
  Helloworld () {  
    cout<< "Constructor function is called" <<endl;  
  }  
  //Destructor  
  ~Helloworld () {  
    cout << "Destructor function is called" <<endl;  
   }  
   //Member function  
   void display() {  
     cout <<"Hello World!" <<endl;  
   }  
};  
int main(){  
   //Object created  
   Helloworld obje;  
   //Member function called  
   obje.display();  
   return 0;  
}  

OUTPUT:

Hello World!
…………………….
Process exited with return value 0
Press any key to continue.

In C++ programming, there is a distinction between constructors and destructors as follows:

CharacteristicsConstructor in C++Destructor in C++
MotiveIn C++, we used a function Object () {[native code]} to allocate memory to the object.In C++, we use the concept of destructor to de-allocate the memory that the function Object () { [native code] } allocated to an object for this purpose.
ArgumentsIt could include or exclude arguments.It is unable to accommodate the arguments.
CallingIt is invoked automatically whenever a class object is generated.When the application ends, it automatically calls this function.
RAMThe function Object () { [native code] } uses memory.Memory is released by the Destructor.
Returning TypesIt has different return types.There is no return type for it.
Special SymbolThe special symbol is not required when declaring constructors in the C++ programming language.A specific sign, the tilde symbol, is necessary when defining a destructor in the C++ programming language.
Number of UseIn our program, we can utilize many constructors.The program cannot have more than one destructor.
Way of DeclarationTo create a function Object() { [native code] }, use the following declaration: class Name { ………. public Name ([parameter list]) { ………………. } };To create a destructor, use the following declaration: class Name { …………….; …………….; public: ~abc();  { …………         };



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