Write a C++ program to demonstrate the use of constructors and destructors.

Write a C++ program to demonstrate the use of constructors and destructors.

Algorithm:

Step 1: Create a class

Step 2: Create a constructor for this class which will set the value of its member variables.

Step 3: Create the other required methods for the given class

Step 4: Define the destructor.

Step 5: Create an object of this class

Step 6: The constructor will be called upon creation and when the program is ending the destructor will be called.

Program Code:

#include<iostream.h>

class Arr

{

int m,n;

int **a;

public:

Arr(int x,int y);

Arr(Arr &c)

{

a=c.a;

m=c.m;

n=c.n;

}

void getd();

void shd();

~Arr()

{

delete a;

}

};

Arr::Arr(int x,int y)

{

m=x;

n=y;

a=new int*[m];

for(int i=0;i<m;i++)

a[i]=new int[n];

}

void Arr::getd()

{

int j;

cout<<"\nEnter the matrix elements:";

for(int i=0;i<m;i++)

for(j=0;j<n;j++)

cin>>a[i][j];

}

void Arr::shd()

{

int j;

cout<<"\n\nMatrix elements:\n";

for(int i=0;i<m;i++){

for(j=0;j<n;j++)

cout<<a[i][j]<<" ";

cout<<endl;}

}

int main()

{

int m,n;

cout<<"Enter the size of matrix needed:";

cin>>m>>n;

Arr t(m,n),s(t);

cout<<"By help of constructor:";

t.getd();

t.shd();

cout<<"By help of copy constructor:";

s.shd();

s.getd();

s.shd();

return 0;

}

Output:

Enter the size of matrix needed: 2 2

By help of constructor:

Enter the matrix elements:

1 2

3 4

Matrix Elements

1 2

3 4

By help of copy constructor:

Matrix Elements

1 2

3 4

Enter the matrix elements:

1 2

3 4

Matrix Elements

2 2

3 4