How to Use stringstream for Input With Spaces in C++?

In C++, the std::stringstream class is a stream class to operate on strings and is very useful when we want to operate on a string as if it were a stream (like cin or cout). In this article, we will learn how to use string streams for input with spaces in C++.

Example:

Input: 
string = “Hello, World!”

Output: 
Hello, World! //Read the string into a string stream and output each word

Taking Input with Spaces Using stringstream in C++

In C++, the stringstream is used to create a stream to a string. This stream can be used to read the data from the string using >> (extraction operator) but it will read the input till the whitespace. The rest of the input would require more use of the>> operator making it not suitable for working with input strings with spaces.

To use stringstream for strings with spaces, we can use the std::getline() function that can read from the stream till the given delimiter.

Syntax of std::getline() in C++

getline(stream, dest, delim)

Here,

• stream: stream to read data from
• dest: string variable that will hold the read data.
• delim: delimiter that specifies where to stop reading.

C++ Program to Use String Streams for Input with Spaces

The below example demonstrates how to use string streams for input with spaces in C++.

C++

// C++ Program to illustrate how to use stringstream for input with spaces
#include <iostream>
#include <sstream>
using namespace std;

int main()
{
    // Initialize a string
    string myString = "Hello, World!";

    // Use stringstream for input with spaces
    stringstream ss(myString);
    string word;
    while (getline(ss, word, '\0')) {
        cout << word << endl;
    }

    return 0;
}

Hello, World!

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