Methods to concatenate string in C/C++ with Examples

There are various ways to concatenate strings. We will discuss each one by one.

Method 1: Using strcat() function.

The strcat() function is defined in “string.h” header file.

Syntax:

char * strcat(char * init, const char * add)

The init and add string should be of character array(char*). This function concatenates the added string to the end of the init string.

Example:

#include <bits/stdc++.h>
using namespace std;

int main()
{
    char init[] = "this is init";
    char add[] = " added now";

    // concatenating the string.
    strcat(init, add);

    cout << init << endl;

    return 0;
}

Output:

this is init added now

Method 2: Using append() function.

Syntax:

string& string::append (const string& str)

str: the string to be appended.

Here str is the object of std::string class which is an instantiation of the basic_string class template that uses char (i.e., bytes) as its character type. The append function appends the add(variable) string at the end of the init string.

Example:

#include <bits/stdc++.h>
using namespace std;

int main()
{
    string init("this is init");
    string add(" added now");

    // Appending the string.
    init.append(add);

    cout << init << endl;
    return 0;
}

Output:

this is init added now

Method 3: Using ‘+’ Operator

Syntax:

string new_string = string init + string add;

This is the most easiest method for concatenation of two string.The + operator simply adds the two string and returns a concatenated string.

Example:

#include <bits/stdc++.h>
using namespace std;

int main()
{
    string init("this is init");
    string add(" added now");

    // Appending the string.
    init = init + add;

    cout << init << endl;
    return 0;
}

Output:

this is init added now