C++ Program for String Concatenation

Hello Everyone!

In this tutorial, we will learn how to Concatenate Two Strings entered by the user, in the C++ programming language.

String Concatenation:

In programming, String Concatenation refers to combining two strings into a single resultant string without modifying each of the individual strings.

It is performed by using the '+' operator in between two strings.

After Concatenation operation, the length of the resultant string is the sum of both the individual strings.


String1 = Study

String2 = tonight

String3 = String1 + String2 = Studytonight

The below code demonstrates its implementation in C++.


#include <iostream>

//This header file is used to make use of the strncpy() method
#include <string.h>

using namespace std;

int main()
    cout << "\n\nWelcome to Studytonight :-)\n\n\n";
    cout << " =====  Program to Concatenate Two Strings in CPP  ===== \n\n";

    //Variable Declaration
    string s1, s2, s3;

    cout << "\n\nEnter the first String without any space : ";
    cin >> s1;

    cout << "\nEnter the second String without any space : ";
    cin >> s2;

    cout << "\n\nThe two individual Strings before Concatenation are :\n\n";
    cout << "String1 = " << s1 << " and its lenght is " << s1.size() << "\n";
    cout << "String2 = " << s2 << " and its lenght is " << s2.size() << "\n\n";

    //Performing Concatenation of two strings using the + operator in CPP
    s3 = s1 + s2;

    cout << "\n\nThe resulting string after the Concatenation of the two strings is :\n\n";
    cout << "String3 = String1 + String2\n";
    cout << "String3 = " << s3 << " and its lenght is " << s3.size() << "\n\n";

    cout << "\nNote: Length of String3 is sum of the individual lengths of both the strings.";

    cout << "\n\n";

    return 0;


C++ string Concatenation

We hope that this post helped you develop better understanding of the concept of String Concatenation in C++. For any query, feel free to reach out to us via the comments section down below.

Keep Learning : )