Inheritance from String class - C++ Class

C++ examples for Class:Inheritance

  1. HOME
  2. C++
  3. Class
  4. Inheritance

Description

Inheritance from String class

Demo Code

                                                                                                                                                                                                                    
#include <iostream>
#include <cstring>                //for strcpy(), etc.
using namespace std;
class String                      //base class
{
protected:                     //Note: can't be private
  enum { SZ = 80 };           //size of all String objects
  char str[SZ];               //holds a C-string
public://from  w  w  w  .j  a  va2 s  .c  o m
  String()                    //constructor 0, no args
  {
    str[0] = '\0';
  }
  String(char s[])          //constructor 1, one arg
  {
    strcpy(str, s);
  }      //  convert string to String
  void display() const        //display the String
  {
    cout << str;
  }
  operator char*()            //conversion function
  {
    return str;
  }          //convert String to C-string
};
class Pstring : public String     //derived class
{
public:
  Pstring(char s[]);        //constructor
};
Pstring::Pstring(char s[])      //constructor for Pstring
{
  if (strlen(s) > SZ - 1)           //if too long,
  {
    int j = 0;
    for (j = 0; j<SZ - 1; j++)   //copy the first SZ-1
      str[j] = s[j];           //characters "by hand"
    str[j] = '\0';              //add the null character
  }
  else                           //not too long,
    String(s);                  //so construct normally
}
int main()
{                                        //define String
  Pstring s1 = "This is a very long string. This is a very long string. This is a very long string. This is a very long string. ";
  cout << "\ns1="; s1.display();           //display String
  Pstring s2 = "This is a short string.";  //define String
  cout << "\ns2="; s2.display();           //display String
  cout << endl;
  return 0;
}

Result


Related Tutorials