PROGRAM FOR DYNAMIC CONSTRUCTOR

//program using dynamic constructor
#include<iostream.h>
#include<string.h>
#include<conio.h>
class string
{
  char *name;
  int length;
  public:
  string()
  {
    length=0;
    name=new char[length+1];
  }
  string(char *s)
  {
   length=strlen(s);
   name=new char[length+1];
   strcpy(name,s);
  }
  void display()
  {
    cout<<name<<endl;
  }
  void join(string &,string &);
};
void string::join(string &a,string &b)
{
   length=a.length+(b.length);
   name=new char[length+1];
   strcpy(name,a.name);
   strcat(name,b.name);
}
void main()
{
  char *first="SATHI";
  string n1(first);
  string n2("SH"),n3("KUMAR");
  string s1,s2;
  clrscr();
  s1.join(n1,n2);
  s2.join(s1,n3);
  n1.display();
  n2.display();
  n3.display();
  s1.display();
  s2.display();
  getch();
}