Stringstream in C++ and its applications

In this tutorial, we will explore what the stringstream in C++ is. We will also learn its application.

What is stringstream?

With the aid of a stringstream, user can read from a string object as though it were a stream (like cin). sstream header file inclusion is required in order to use stringstream. Input parsing benefits greatly from the use of the stringstream class.

Common techniques are:

1. clear() - It is used to empty the stream.
2. str() – It can be used to retrieve and modify string objects with content that is present in the stream.
3. operator << - To the stringstream object, add a string.
4. operator >> - Read from the stringstream object using the operator >>.

Let's look at two string stream examples in below.

Example 1: We will separate the words into individual strings in this program.

C++ Code:

#include <iostream>
#include <vector>
#include <string>
#include <sstream>
using namespace std;


int main () 
{
   string str (" Hey Mr. don't move ");
   
   // declaring a string that will be used to preserve word each time.
   string abc; 
   
   // Using a string stream to separate input into words
   stringstream str_strm ( str ); 
   
   // Considering a vector that can contain our words.
   vector < string > splt; 
   
   // Using while loop
   while ( str_strm >> abc ) 
   {
      
      // pushing in abc
      splt.push_back ( abc );
   }
   
   // using for loop
   for ( int index = 0; index < splt.size(); index ++ )
      cout << splt [ index ] << endl;
}

Output:

Hey
Mr.
don't
move

Example 2: The total number of words in a given string will be determined by this program.

C++ Program:

#include <iostream>
#include <iostream>
#include <sstream>
#include <string>
using namespace std;


int cntw ( string str )
{
	//Using a string stream to separate input into words
	stringstream a ( str );


	// declaring a string that will be used to preserve words individually
	string www;


	// declaring a variable to keep counts of words
	int ct = 0;
	
	// using while loop
	while ( a >> www )
		ct ++;
	return ct;
}


// main function 
int main ()
{
	string a = " My dream is to be a successful Technical Content Developer";
	cout << " The total number of words are: " << cntw ( a );
	return 0;
}

Output:

The total number of words are: 10

From the above two programs, we learn how to utilize stringstream in a C++ Code.