C++ File handling: Count number of words in a text file

Last update on April 14 2025 12:41:51 (UTC/GMT +8 hours)

4. Count the Number of Words in a Text File

Write a C++ program to count the number of words in a text file.

Sample Solution:

C Code:

#include <iostream>     // Including the input/output stream library
#include <fstream>      // Including the file stream library
#include <string>       // Including the string handling library
#include <sstream>      // Including the stringstream library

int main() {
  std::ifstream inputFile("test.txt"); // Open the text file named "test.txt" for reading

  if (inputFile.is_open()) {  // Checking if the file was successfully opened
    std::string line;         // Declaring a string variable to store each line of text
    int wordCount = 0;        // Initializing a variable to count words

    while (std::getline(inputFile, line)) {  // Loop through each line in the file
      std::stringstream ss(line);  // Create a stringstream object with the current line content
      std::string word;  // Declare a string variable to store each word

      while (ss >> word) {  // Extract words from the stringstream
        wordCount++;  // Increment word count for each word extracted
      }
    }

    inputFile.close();  // Closing the file after counting words

    std::cout << "Number of words in the said file: " << wordCount << std::endl;  // Outputting the total word count
  } else {
    std::cout << "Failed to open the file." << std::endl;  // Display an error message if file opening failed
  }

  return 0;  // Return 0 to indicate successful execution
}

Sample Output:

Number of words in the said file: 76

Explanation:

In the above exercise,

• Use the std::ifstream class to open the text file.
• Check if the file was successfully opened using the is_open() function.
• If the file is open, declare an int variable wordCount to keep track of the number of words.
• Then use a while loop and std::getline() to read each line from the file. Inside this loop, use std::stringstream to break the line into individual words.
• Use another while loop with ss >> word to extract each word and increment the wordCount for each word encountered.
• Display the total number of words on the console after the loops end using inputFile.close().

Flowchart:

For more Practice: Solve these Related Problems:

• Write a C++ program to open a text file and count the words by reading each line and splitting by spaces.
• Write a C++ program that uses string streams to parse each line of a file and count the total number of words.
• Write a C++ program to read a file and count words by iterating through each character and detecting word boundaries.
• Write a C++ program to process a text file and output the number of words, ignoring punctuation and multiple spaces.

CPP Code Editor:

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