boost::algorithm::join() in C++ Library

Last Updated : 09 Mar, 2022

The library Boot.StringAlgorithms provides many functions for string manipulations. The string can be of type std::string, std::wstring, or any instance of the class template std::basic_string.

boost::algorithm:join():

The join() function in the C++ boost library is included in the library "boost/algorithm/string". This function is used to join two or more strings into one long string by adding a separator between the strings. The strings to be joined are provided in a container like a vector of string. Popular used containers are std::vector<std::string>, std::list<boost::iterator_range<std::string::iterator>.

Syntax:

join(container, separator)

Parameters:

container: It contains all the strings which have to be joined.
separator: It is a string that separates the joined strings.

Example 1: Below is the C++ program to implement the above approach.

C++

// C++ program for the
// above approach
#include <boost/algorithm/string.hpp>
#include <iostream>
using namespace std;
using namespace boost::algorithm;

// Function to join 2 or more strings
void concatenate(vector<string>& v1)
{
    // Joining the strings with a 
    // whitespace
    string s1 = boost::algorithm::join(v1, " ");

    cout << s1 << endl;

    // Joining the strings with a '$'
    string s2 = boost::algorithm::join(v1, "$");

    cout << s2 << endl;
}

// Driver Code
int main()
{
    // Vector container to hold 
    // the input strings
    vector<string> v1;

    v1.push_back("Geeks");
    v1.push_back("For");
    v1.push_back("Geeks");

    // Function Call
    concatenate(v1);

    return 0;
}

Output

Geeks For Geeks
Geeks$For$Geeks

Example 2: Below is the C++ program to implement the above approach.

C++

// C++ program for the above approach
#include <iostream>
#include <boost/algorithm/string.hpp>
using namespace std;
using namespace boost::algorithm;

// Function to join 2 or more strings
void concatenate(vector<string>& v1)
{
    // Joining the strings with 
    // the string "..."
    string s1 = boost::algorithm::join(v1, "...");

    cout << s1 << endl;
}

// Driver Code
int main()
{
    // Vector container to hold the 
    // input strings
    vector<string> v1;

    v1.push_back("Geeks");
    v1.push_back("For");
    v1.push_back("Geeks");

    // Function Call
    concatenate(v1);

    return 0;
}