Stringstream trong C++ là gì

A stringstream associates a string object with a stream allowing you to read from the string as if it were a stream (like cin). To use stringstream, we need to include sstream header file. The stringstream class is extremely useful in parsing input. 

Basic methods are:

1. clear()- To clear the stream.
2. str()- To get and set string object whose content is present in the stream. 
3. operator <<- Add a string to the stringstream object. 
4. operator >>- Read something from the stringstream object.

Examples:

1. Count the number of words in a string

Examples:

Input: Asipu Pawan Kumar
Output: 3

Input: Geeks For Geeks Ide
Output: 4

Below is the C++ program to implement the above approach-

C++

// C++ program to count words in 

// a string using stringstream.

#include

#include

#include

using namespace std;

 

For-> 1
Geeks-> 2
Ide-> 1

0

For-> 1
Geeks-> 2
Ide-> 1

1

For-> 1
Geeks-> 2
Ide-> 1

2

For-> 1
Geeks-> 2
Ide-> 1

3

For-> 1
Geeks-> 2
Ide-> 1

4

For-> 1
Geeks-> 2
Ide-> 1

3

For-> 1
Geeks-> 2
Ide-> 1

6

For-> 1
Geeks-> 2
Ide-> 1

7 

For-> 1
Geeks-> 2
Ide-> 1

3

For-> 1
Geeks-> 2
Ide-> 1

9

For-> 1
Geeks-> 2
Ide-> 1

3// C++ program to count words in 1

For-> 1
Geeks-> 2
Ide-> 1

7 

For-> 1
Geeks-> 2
Ide-> 1

3// C++ program to count words in 4

For-> 1
Geeks-> 2
Ide-> 1

3// C++ program to count words in 6

 

For-> 1
Geeks-> 2
Ide-> 1

3

For-> 1
Geeks-> 2
Ide-> 1

0 // C++ program to count words in 9

For-> 1
Geeks-> 2
Ide-> 1

3// a string using stringstream.1 // a string using stringstream.2

// a string using stringstream.3// a string using stringstream.4

For-> 1
Geeks-> 2
Ide-> 1

3// a string using stringstream.6 // a string using stringstream.7

// a string using stringstream.8

 

// a string using stringstream.9

For-> 1
Geeks-> 2
Ide-> 1

0 #include 1

For-> 1
Geeks-> 2
Ide-> 1

2

For-> 1
Geeks-> 2
Ide-> 1

3#include 4#include 5

#include 6#include 7#include 8

For-> 1
Geeks-> 2
Ide-> 1

3#include 0#include 1 #include 2

For-> 1
Geeks-> 2
Ide-> 1

3// a string using stringstream.6 #include 5

// a string using stringstream.8

Output

 Number of words are: 6

2. Print frequencies of individual words in a string

Examples:

Input: Geeks For Geeks Quiz Geeks Quiz Practice Practice
Output: For -> 1
             Geeks -> 3
             Practice -> 2
             Quiz -> 2

Input: Word String Frequency String
Output: Frequency -> 1
              String -> 2
              Word -> 1     

Below is the C++ program to implement the above approach-

C++

#include 7

#include 8

#include 9

#include0

#include

#include

#include

using namespace std;

 

#include7 #include8

For-> 1
Geeks-> 2
Ide-> 1

2

For-> 1
Geeks-> 2
Ide-> 1

3using1

For-> 1
Geeks-> 2
Ide-> 1

3using3

For-> 1
Geeks-> 2
Ide-> 1

3using5

For-> 1
Geeks-> 2
Ide-> 1

0using7

For-> 1
Geeks-> 2
Ide-> 1

7 

For-> 1
Geeks-> 2
Ide-> 1

3

For-> 1
Geeks-> 2
Ide-> 1

9

For-> 1
Geeks-> 2
Ide-> 1

3namespace2

For-> 1
Geeks-> 2
Ide-> 1

7 

For-> 1
Geeks-> 2
Ide-> 1

3// C++ program to count words in 4

For-> 1
Geeks-> 2
Ide-> 1

3namespace7

 

For-> 1
Geeks-> 2
Ide-> 1

3// a string using stringstream.1 std;0

// a string using stringstream.3std;2

 

For-> 1
Geeks-> 2
Ide-> 1

3using5

For-> 1
Geeks-> 2
Ide-> 1

0std;6

For-> 1
Geeks-> 2
Ide-> 1

3std;8 std;9

// a string using stringstream.3

For-> 1
Geeks-> 2
Ide-> 1

01

For-> 1
Geeks-> 2
Ide-> 1

02

For-> 1
Geeks-> 2
Ide-> 1

03

For-> 1
Geeks-> 2
Ide-> 1

04

For-> 1
Geeks-> 2
Ide-> 1

05#include 8

// a string using stringstream.8

 

// a string using stringstream.9

For-> 1
Geeks-> 2
Ide-> 1

0 #include 1

For-> 1
Geeks-> 2
Ide-> 1

2

For-> 1
Geeks-> 2
Ide-> 1

3#include 4

For-> 1
Geeks-> 2
Ide-> 1

14#include 8

For-> 1
Geeks-> 2
Ide-> 1

3

For-> 1
Geeks-> 2
Ide-> 1

17

For-> 1
Geeks-> 2
Ide-> 1

3// a string using stringstream.6 #include 5

// a string using stringstream.8

Output

For-> 1
Geeks-> 2
Ide-> 1

Removing spaces from a string using Stringstream
Converting Strings to Numbers in C/C++

This article is contributed by ASIPU PAWAN KUMAR. If you like GeeksforGeeks and would like to contribute, you can also write an article using write.geeksforgeeks.org or mail your article to [email protected]. See your article appearing on the GeeksforGeeks main page and help other Geeks.