Question

In C++

PART 1: Write a constructor for a class data type named Test that has the following two member variables:

double arr*;
int size;

The constructor should take one argument for the size and then dynamically allocate an array of that size.

PART 2: Write a destructor for the Test class.

Answer 1

Constructor: A member function of a class with same name as class which usually deals with creating memory and initialising the the data members of the class. constructor will be called by compiler to create an object

Destructor: A destructor a member function of a class which deletes the allocated memory for the class. once the object goes out of scope destructor will be called by compiler

To create dynamic memory we can use new keyword and to delete memory allocated by new we can use delete keyword. To delete an array of memory use delete[]

CODE:

#include <iostream>

//part 1

// class data type named Test

class Test{

//that has the following two member variables:

double *arr;

int size;

//Write a constructor for a class - should be public to create objects

public:

//The constructor should take one argument for the size and then dynamically allocate an array of that size.

Test(int s){

//std::cout<<"Constructor called\n";

size=s;

arr=new double[size];

}

//part 2

//Write a destructor for the Test class

~Test(){

//std::cout<<"Destructor called\n";

delete[] arr;

}

};

int main() {

//Sample Object t creation

Test t(10);

}

Note: Un comment the std::cout statements to understand the automatic behaviour of object management in c++