How do you write a C plus plus program to concatenate any two strings using operator overloading?

Answer 1

#include "stdafx.h"

#include<iostream>

#include<conio.h>

using namespace std;

class Add{

public:

char *rep;

Add(){}

Add(char *tem){

rep = new char[strlen(tem)+1] ;

strcpy(rep,tem);

}

Add operator + (const Add &rhs)

{

char *temp;

temp= new char[strlen(rep) + strlen(rhs.rep)+1];

temp = strcat(rep,rhs.rep);

return Add(temp);

}

};

int main()

{

cout<<"hello";

Add obj1("pradeep");

Add obj2("bansal");

Add obj3;

obj3 = obj1+obj2;

cout<<obj3.rep;

getch();

return 0;

}

Answer 2

#include

int main()

{

std

::

string a

=

"Hello "

;

std

::

string b

=

"World"

;

std

::

string c

=

a

+

b

;

return( 0 );

}

Answer 3

The C++ standard library already provides string concatenation in <string>. If you wish to cater for a user-defined string T, use the following implementation:

T operator+ (const T& str1, const T& str2) {

T s { str1 }; // copy the first string

s += str2; // append the second string

return s;

}

Note that you must provide an implementation for the T::operator+= member function. Expressing non-member functions in terms of member functions is standard practice and helps ensure consistency between the two.

For a string object, the implementation of T::operator+= should be similar to the following:

T& T::operator+= (const T& str) {

if (reserve() < str.size()) resize (size() + str.size());

for (auto c : str) append (c);

return *this;

}

The exact implementation will depend upon how your string is implemented.

Note that implementing your own string type is a useful exercise while learning the language, but for real-world applications you should use the std::string type provided by the standard library. It is extremely efficient and the class template can cater for any type of character, including user-defined characters. Consult the source code to get a better understanding of how string concatenation should be implemented.