default constructor in c++

#include <iostream>
class Entity {
	
public: 
	float x, y;
	void Print() {
		std::cout << "( " << x << " , " << y << " )" << std::endl;
	}
	void Initialize() {
		x = 0.0f;
		y = 0.0f;
	}//This method initialize x and y to 0

	Entity() {
		//A constructor is a function that will get called everytime you intantiate a class
		//1) A constructor function looks like this name of function  must be == to classname 
		//2) This function must not return anything 
		x = 0.f; y = 0.0f;//constructor will initalize the x and y to 0 when we will create an instance of class
		//we can use constructor member initializer list to initialize our variables which is better than using constructor check that out
	}
};
//2 using constructor with parameters 
class Entity2 {
public:
	float X, Y;
	Entity2(float x, float y) {
		X = x;
		Y = y;
		std::cout << "this is x: " << x << " this is y: " << y << std::endl;
		//Using constructor with parameters will create an instance of object with these parameters and output x an y
	};
};
class DefaultC {
private:
	/*
	DefaultC() {
		//making default constructor private will not construct an instantiate an object
	};
	*/
public:
	int a;
	/*
	DefaultC() {
		//This is a default construtor that creates an object without prameters  and if make it private or delete it we ca'nt construct the object
		T// This is default constructor and gets called always when you create object with no parameters and deleting it or making it private you will not be able to construct an object
		};
	*/
	DefaultC() = delete; //making default constructor private will not construct an instantiate an object
};
int main() {
	Entity e;
	e.Print();//output => because Printing the uninitialised memory (-1.07374e+08, -1.07374e+08)
	//std::cout << e.x << std::endl; // Error => uninitialised local variable e used
	

	//Instead we can call Initialize method that will initialize to set x and y to 0.0
	//this will work but is not the best way 
	Entity e1;
	e1.Initialize();// using this method to initialize x and y
	e1.Print();// output => (0,0)
	std::cout << e1.x << std::endl;// output => 0

	//But the above is no a good practice we can use a constructor instead
	//A constructor is a function that will get called everytime we instantiate an object
	
	Entity e2;
	e2.Print();//output => (0,0)
	std::cout << e2.x << std::endl;//output => 0
    // This time we don't have to call any method the constructor initialized our x and y var on inistantiating an object
	
	std::cout << "=================================================" << std::endl;
	
	Entity2 entity(2.2f,3.3f); // create entity with parameters and will output x and y
	//Entity2 entity2;  //error =>	no default constructor exists for class "Entity2"	 this is because we have not specified the default constructor we specified a constructor that will take parameters x and y and will construct an object on these parameters
	
	//Default constructor is expalined below
	DefaultC C;// error =>  Default C constructor is inaccessible because we deleted it or made it private
	//To avoid this just the delete line and the private constructor and  you will bee good

	std::cin.get();
}

Are there any code examples left?
Create a Free Account
Unlock the power of data and AI by diving into Python, ChatGPT, SQL, Power BI, and beyond.
Sign up
Develop soft skills on BrainApps
Complete the IQ Test
Relative searches
how to write default constructor in c++ create object with default constructor c++ how to define default constructor in c++ how to create default constructor for a class c++ hwo to create default constructor fo a class c++ c++ how to make a defualt constructor how to implement default constructor in c++ java c++ constructor = default nedir default constructor c++ nedir c++ program to demonstrate default constructor default constructor in c++ programiz c++ constructor set default values = default constructor c++ c++ do you need a default constructor c++ define default constructor c++ default constructor = default does cpp have default constructor how to set default value in constructor cpp c++ concept require default constructor c++ with what do you start a default constructor constructor default value c++ what is default constructor in c++ with example c++ constructor = default c++ 11 default constructor default constructor in cpp how to set default value of a constructor in c++ C++ class default constructor values constructor c++ default values a default constructor c++ default constructor c++11 when object is created is default constructor called in C plus plus default c++ constructor c++ default constructor automatically generated when calling with () default constructor code in c++ c++ default constructor and constructor example c++ declaration default constructor c+ default constructor what are default constructor in c++ c++ use struct default constructor setting default value of a constructor in c++ c++ structure default constructor default constructor in c++ with examples default constructor example in c++ default constructors example c++ constructor with default parameters c++ example constructor with default parameters c++ does cpp generate a default constructor does is default constructor in c++ how to invoke a default constructor in c++ how to do a default constructor c++ c++ provide its own default constructor default constructer c++ syntax for default constructor in c++ default class constructor c++ c++ default constructor initialization default constructor in c++ example use of default constructor in c++ c++ default constructors how to create a default constructor in c++ c++ make constructir = default what does it mean to set a constructor to default c++ default construct in c++ c++ calling default constructor c++ enable default constructor c++ how to initialize in default constructor default constructor in c++ syntax create default constructor c++ is it mandatory to have a default constructor in c++ using struct constructor c++ default does struct have default constructor c++ c++ constructor default values how to call default value constructor c++ c++ class with default constructor c++ default value in constructor default values constructor c++ is it compulsory to create default constructor in c++ c++ default values in constructor struct default constructor c++ default constructor struct cpp c++ set default value in constructor how to create default constructor in c++ using default values how to create default constructor in c++ set default value in constructor c++ default constructible c++ meaning c++ automatic create default constructor deafult constructor c++ =default constructor c++ can we define default constructor in c++ what is default constructor in c++ cpp generates a defult constructor set default constructor c++ c++ struct default constructor example how to call default constructor c++ default value constructor c++ is initialisation done in default constructor in c + + default constructor in c + + c++ when do you need a default constructor constructor default values c++ c++ default constructor for object default constructor creating a object c++ how to set default constructor c++ default values for constructor c++ c++ class default constructor purpose Constructor in c++ implementation default is default constructor always generated C++ c++ when is default constructor generated when do you have to define default constructor C++ when do you have to define default constructor C++_ do you need to define a default constructor c++ c++ does compiler create default constructor? default constructor of a class c++ class default constructor c++ cpp struct default constructor default constructor in c++ advantages default constructor in c++ program can we have a constructor and a default contructor in c++ c++ struct default constructor constructors c++ set default value c++ class constructor default values in cpp c++ class constructor default values c++ create default constructor c++ class default constructor Program to show the use of Default Constructor c++ how to set a default constructor for my class c++ default constructor example c++ default values constructor in c++ classes c++ default constructors default constructor is created by in c++ implement class default constructor c++ implement default constructor c++ c++ make default constructor default constructor of a class in c++ cpp default constructor example c++ set default constructor who provides the default constructor in cpp default values in constructor c++ constructor default c++ copy constructor in c++ default constructors in c++ C++ when to define the default constructor c++ default class constructor the generated default constructor default parameters c++ c++ default argument cpp default constructor default parameter cpp default value in c++ default arguements in c++ default parameters in function c++ default constructors default parameters in c++ constructor default constructor and destructor in c++ explicitly default constructor in c++ c++ implicite constructor default constructors c++ how to make a default constructor c++ c++ declare default constructor which default constructor is running in c++ what does default constructor do in c++ c++ default constructor example what is a default constructor in c++ c++ constructor default example of default constructor in c++ default cpnstructor c++ what is a default constructor Default constructor can be defined as what is a default constructor c++ does c++ add default constructor default constructor meaning constructor = default c++ defined default funtion in constructor what is default constructor include in c++ what is a default constructor for c++ what is the use of a default constructor c++ what is a default construstor in C++ how to make default constructor in c++ c++ what is the primary purpose of a default constructor with default parameter c++ default constructor class default constructor cpp how to create a simple default constructor in c++ Default constructors are _______ by default. do default constructors need to be defined default constructor deafault constuctor c++ C++ howq to write a default constructor default constructor c++ example how to use the default constructor in c++ How do we execute the default constructor in c++ what does default constructor look like in .cpp file default constructor c++ declaring default constructor c++ c++ default constructor creating a default constructor c++ default constructor in c++
Made with love
This website uses cookies to make IQCode work for you. By using this site, you agree to our cookie policy

Welcome Back!

Sign up to unlock all of IQCode features:
  • Test your skills and track progress
  • Engage in comprehensive interactive courses
  • Commit to daily skill-enhancing challenges
  • Solve practical, real-world issues
  • Share your insights and learnings
Create an account
Sign in
Recover lost password
Or log in with

Create a Free Account

Sign up to unlock all of IQCode features:
  • Test your skills and track progress
  • Engage in comprehensive interactive courses
  • Commit to daily skill-enhancing challenges
  • Solve practical, real-world issues
  • Share your insights and learnings
Create an account
Sign up
Or sign up with
By signing up, you agree to the Terms and Conditions and Privacy Policy. You also agree to receive product-related marketing emails from IQCode, which you can unsubscribe from at any time.
Creating a new code example
Code snippet title
Source