How to Split a String Based on Empty/Blank Lines in C++?

In C++, strings are objects that represent a sequence of characters and we can break this string into a new line using the '\n' escape sequence. In this article, we will learn how to split a string by empty or blank lines in C++.

Example:

Input:
string inputString= "Hello\n\nWorld\n\nThis\n\nis\n\nGeeksForGeeks";

Output:
Hello
World
This
is
GeeksForGeeks

Split a String into Words by Empty Lines in C++

To split a std::string by empty lines, we can use the stringstream with a combination of std::getline function having ‘\n’ as the delimiter. We can keep taking input using getline() till there is no string left.

Approach

• Create a stringstream to the given string.
• Create a string variable to store the splitter strings.
• Run a loop using std::getline with ‘\n’ as the delimiter.
• If the line is not empty, add it to the result.
• Repeat the process until the end of the string is reached.

C++ Program to Split a String Based on Empty/Blank Lines

The below program illustrates how we can split a string based on empty/blank lines in C++.

// C++ Program to illustrate how to split a string by empty
// or blank lines
#include <iostream>
#include <sstream>
#include <string>
#include <vector>
using namespace std;

// Function to split a string by empty lines
vector<string> splitStringByEmptyLines(string& inputString)
{
    vector<string> result;
  
    stringstream ss(inputString);
    string line;

    // Loop until the end of the string
    while (getline(ss, line)) {
        if (!line.empty()) {
            result.push_back(line);
        }
    }

    return result;
}

int main()
{
    // string to be splitted
    string inputString
        = "Hello\n\nWorld\n\nThis\n\nis\n\nGeeksForGeeks";

    // calling the function to split the string by empty
    // lines
    vector<string> substrings
        = splitStringByEmptyLines(inputString);

    // Displaying the string after splitting
    for (const auto& substring : substrings) {
        cout << substring << endl;
    }

    return 0;
}

Hello
World
This
is
GeeksForGeeks

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