How to Split a String into an Array in C++?

Last Updated : 04 Mar, 2024

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

Example:

Input:
str= “Hello, I am Geek from geeksforgeeks” 
Delimiter= ’ ’

Output: 
Hello,
I
am
Geek
from
geeksforgeeks

Splitting a String into an Array in C++

To split a string into an array of substrings in C++, we can use the std::istringstream class from the <sstream> library to create an input stream from the string. We can then split the string based on some delimiter using getline() and store them into the array of strings.

Approach

Create an input string stream from the input string using std::istringstream.
Iterate through the stream, using std::getline to extract each substring separated by the delimiter.
Add the extracted substring to the array.
Print the array of substrings.

C++ Program for Splitting a String into an Array

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

C++

// C++ Program to illustrate how to split a string into an
// array of substrings
#include <iostream>
#include <sstream>
#include <string>

using namespace std;

// Function to split a string into tokens based on a
// delimiter
void splitString(string& input, char delimiter,
                 string arr[], int& index)
{
    // Creating an input string stream from the input string
    istringstream stream(input);

    // 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 array
        arr[index++] = token;
    }
}

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

    // Delimiter
    char delimiter = ' ';

    // Array to store the substrings
    string arrayOfSubStr[100];

    // Index to keep track of the number of substrings
    int index = 0;

    // Calling the function to split the input string into
    // an array of substrings
    splitString(input, delimiter, arrayOfSubStr, index);

    // Print the array of substrings
    for (int i = 0; i < index; i++) {
        cout << arrayOfSubStr[i] << endl;
    }

    return 0;
}

Output

Hello,
I
am
Geek
from
Geeksforgeeks

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