c++ program on constructor overloading (array)

//program based on constructor overloading
#include<stdio.h>
#include<conio.h>
class array
{
int dim,*arr;
public:
void getvalue(void);
void putvalue(void);
array()
{
dim=0;
arr=new int[dim];
}
array(int n)
{
dim=n;
arr=new int[dim];
}
array(array *a)
{
dim=a->dim;
arr=new int[dim];
}
};
void array::getvalue()
{
cout<<"\n enter array elements: ";
for (int i=0;i<dim;i++)
{
cin>>arr[i];
}
}

void array::putvalue()
{
cout<<"\n array elements:\n ";
for (int i=0;i<dim;i++)
{
cout<<"\n"<<arr[i];
}
}
//constructor overloading default,parameterized,copy constructor
void main()
{
int x;
clrscr();
cout<<"\nenter size of array:\n";cin>>x;
array ar1,ar2(x),ar3(&ar2);
ar1.putvalue();
ar2.getvalue();
ar2.putvalue();
ar3.getvalue();
ar3.putvalue();
getch();
}
//output:

value in default object
 array elements:

enter size of array:
3

 enter array elements:  5 4 8

 array elements:

5
4
8
 enter array elements: 9 5 4

 array elements:

9
5
4