SY_BCS_CPP_Slip no :1_1, 2_1, 18_1

Slip no :1_1, 2_1, 18_1

   1. Define a class Message with two data members one character pointer and an integer storing length.

   Implement following functions:

   a) Default constructor and Parameterized constructor                                                     [2+3]

   b) Overload binary + operator to represent concatenation of messages                           [7]

   c) Overload [] operator to return a character at a specific position                                   [8]

   d) Overload = operator to copy one Message object to another.                                                   [5]

   Write a main function that uses the above class and its member functions.                      [5]

#include<iostream>

#include<string.h>

using namespace std;

class String

{

            char *str;

            int len;

            public :

            String()

            {}

            String(char nm[])

            {

                        len=strlen(nm);

                        str=new char[len+1];

                        strcpy(str,nm);

            }

            void display()

            {

                        cout<<"String = "<<str<<endl;

            }

            String operator+(String ob)

            {

                        String temp;

                        temp.len=len+ob.len;

                        temp.str = new char[temp.len+1];

                        strcpy(temp.str,str);

                        strcat(temp.str,ob.str);

                        return temp;

            }

            char operator[](int &index)

            {

                        if(index>=0 && index<len)

                                    return str[index];

                        else

                                    return '_';

            }

            void operator=(String ob)

            {

                        len=ob.len;

                        str= new char[len+1];

                        strcpy(str,ob.str);

            }

};

main()

{

            char s1[20],s2[30];

            cout<<"Enter 1st string : ";        

            cin>>s1;

            cout<<"Enter 2nd string : ";

            cin>>s2;

            String ob1(s1),ob2(s2);

            cout<<"1st string is ";

            ob1.display();

            cout<<"2nd string is ";

            ob2.display();

            cout<<"After concatinated String : ";

            String ob3;

            ob3=ob1+ob2;

            ob3.display();

            cout<<"Enter index to be search in 1st String : ";

            int i;

            cin>>i;

            char ans=ob1[i];

            if(ans!='_')

                        cout<<"Given index charcater is : "<<ans<<endl;

            else

                        cout<<"Enter valid index"<<endl;

            cout<<"Enter String to be copy :";

            cin>>s2;

            String ob4(s2);

            ob1=ob4;

            ob1.display();

}