C++ Program to concatenate two strings using Operator Overloading
Last Updated :
17 May, 2021
Improve
Pre-requisite: Operator Overloading in C++
Given two strings. The task is to concatenate the two strings using Operator Overloading in C++.
Example:
Input: str1 = "hello", str2 = "world" Output: helloworld Input: str1 = "Geeks", str2 = "World" Output: GeeksWorld
Approach 1: Using unary operator overloading.
- To concatenate two strings using unary operator overloading. Declare a class with two string variables.
- Create an instance of the class and call the Parameterized constructor of the class to initialize those two string variables with the input strings from the main function.
- Overload the unary operator
+ to concatenate these two string variables for an instance of the class. - Finally, call the operator function and concatenate two class variables.
Below is the implementation of the above approach:
// C++ Program to concatenate two string
// using unary operator overloading
#include <iostream>
#include <string.h>
using namespace std;
// Class to implement operator overloading
// function for concatenating the strings
class AddString {
public:
// Classes object of string
char s1[25], s2[25];
// Parameterized Constructor
AddString(char str1[], char str2[])
{
// Initialize the string to class object
strcpy(this->s1, str1);
strcpy(this->s2, str2);
}
// Overload Operator+ to concat the string
void operator+()
{
cout << "\nConcatenation: " << strcat(s1, s2);
}
};
// Driver Code
int main()
{
// Declaring two strings
char str1[] = "Geeks";
char str2[] = "ForGeeks";
// Declaring and initializing the class
// with above two strings
AddString a1(str1, str2);
// Call operator function
+a1;
return 0;
}
Output:
Concatenation: GeeksForGeeks
Approach 2: Using binary operator overloading.
- Declare a class with a string variable and an operator function '+' that accepts an instance of the class and concatenates it's variable with the string variable of the current instance.
- Create two instances of the class and initialize their class variables with the two input strings respectively.
- Now, use the overloaded operator(+) function to concatenate the class variable of the two instances.
Below is the implementation of the above approach:
// C++ Program to concatenate two strings using
// binary operator overloading
#include <iostream>
#include <string.h>
using namespace std;
// Class to implement operator overloading function
// for concatenating the strings
class AddString {
public:
// Class object of string
char str[100];
// No Parameter Constructor
AddString() {}
// Parameterized constructor to
// initialize class Variable
AddString(char str[])
{
strcpy(this->str, str);
}
// Overload Operator+ to concatenate the strings
AddString operator+(AddString& S2)
{
// Object to return the copy
// of concatenation
AddString S3;
// Use strcat() to concat two specified string
strcat(this->str, S2.str);
// Copy the string to string to be return
strcpy(S3.str, this->str);
// return the object
return S3;
}
};
// Driver Code
int main()
{
// Declaring two strings
char str1[] = "Geeks";
char str2[] = "ForGeeks";
// Declaring and initializing the class
// with above two strings
AddString a1(str1);
AddString a2(str2);
AddString a3;
// Call the operator function
a3 = a1 + a2;
cout << "Concatenation: " << a3.str;
return 0;
}
Output:
Concatenation: GeeksForGeeks
