How to Split a C++ String into a Vector of Substrings?

Last Updated : 01 Mar, 2024

In C++, splitting a string into a vector of substrings means we have to split the given string into a substring based on a given delimiter and store each substring in a vector. In this article, we will learn how to split a string into a vector of substrings in C++.

Example:

Input: 
str= "Hello, I am Geek from Geeksforgeeks "
Delimiter= ' '
Output:
Hello,
I
am
Geek
from
Geeksforgeeks

Split an std::string into a Vector of Strings in C++

To split a std::string into a std::vector of substrings use the stringstream with a combination of std::string::getline. The below steps shows how to do that:

Approach

Create an input string stream from the input string using the stringstream.
Iterate through the stream, using getline to extract the substring using the delimiter.
Add the extracted substring to the vector.
Print the vector of substrings.

C++ Program to Split a String into Vector of Substrings

The below example demonstrates how we can split a given string into a vector of substrings in C++.

C++

// C++ Program to illustrate how to split a string to vector
// of substring
#include <iostream>
#include <iterator>
#include <sstream>
#include <string>
#include <vector>

using namespace std;

// Function to split a string into tokens based on a
// delimiter
vector<string> splitString(string& input, char delimiter)
{

    // Creating an input string stream from the input string
    istringstream stream(input);

    // Vector to store the tokens
    vector<string> tokens;

    // Temporary string to store each token
    string token;

    // Read tokens from the string stream separated by the
    // delimiter
    while (getline(stream, token, delimiter)) {
        // Add the token to the vector of tokens
        tokens.push_back(token);
    }

    // Return the vector of tokens
    return tokens;
}

int main()
{
    // Input string
    string input = "Hello, I am Geek from Geeksforgeeks";

    // Delimiter
    char delimiter = ' ';

    // calling the function to Split the input string into
    // vector of substring
    vector<string> vecOfSubStr
        = splitString(input, delimiter);

    // Print the vector of substrings
    for (auto& it : vecOfSubStr) {
        cout << it << endl;
    }

    return 0;
}

Output

Hello,
I
am
Geek
from
Geeksforgeeks

Time complexity: O(n), here n is the length of the input string.
Auxilliary Space: O(n)