C++ Output giving incorrect amount

Question

I am trying to write a program that will count the number of words, and number of sentences, and then take the average of those sentences. It takes the input from a user and will stop taking the input upon seeing "@@@". My code is as follows:

#include <iostream>
#include <iomanip>
#include <cstdlib>
#include <string>
using namespace std;

int main() ///Main
{

    //1. Declaration of variables

    string text;
    double word_count = 0.0;
    double sentence_count = 0.0;
    double avg_words_per_sentence;

    //2. Prompt user input

    cout << "Enter a paragraph..." << endl;
    getline(cin, text, '@'); //3. Use getline to read whole paragraph and not first word entered

    //4. Loop to read through text inputted and determine number of words and sentences

    for (int i = 0; i < text.length(); i++) 
    {
        if (text[i] == ' ')
        {
            word_count++;
        }
        
        else if (text[i] == '.' || text[i] == '!' || text[i] == '?') 
        {
            sentence_count++;
        }
    }
    
    //5. Provides error if there is no text

    if (word_count == 0 && sentence_count == 0) 
    {
        cout << "Word count: " << word_count << endl;
        cout << "Sentence count: " << sentence_count << endl;
        cout << "You did not enter any text!" << endl;
    }
    
    //6. Provides an error if there are no sentences 

    else if (sentence_count == 0) 
    {
        cout << "Word count: " << word_count + 1 << endl;
        cout << "Sentence count: " << sentence_count << endl;
        cout << "You did not enter any sentences!" << endl;
    }
    
    //7. Calculates and outputs word/sentence count and average # of words

    else 
    {
        word_count++;
        avg_words_per_sentence = word_count / sentence_count;
        cout << "Word count: " << word_count << endl;
        cout << "Sentence count: " << sentence_count << endl;
        cout << "Average words per sentence: " << fixed << setprecision(1) << avg_words_per_sentence << endl;
    }

    return 0;
}

For example: If I were to use the input:

ttt

@@@

I would expect my word count to be 1, but I am instead told that it is 2. I am unsure as to why it is counting 2.

I tried tweaking certain if/then statements such as if the string contain "@" to not count the word or only count words if there is a space after a proper character but I am still met with the same incorrect number of words

Answer 1

For starters, you have no need to store word and sentence counts as doubles, and this will cause you problems later in your comparisons for conditions: if (word_count == 0 && sentence_count == 0) should never be done for non integer types.

Your other 'issue' is your own doing, you have 3 cases at the end:

    if (word_count == 0 && sentence_count == 0) 
    {
        cout << "Word count: " << word_count << endl;
        cout << "Sentence count: " << sentence_count << endl;
        cout << "You did not enter any text!" << endl;
    }

All is as expected (assuming word_count and sentence_count are not floating point)

    else if (sentence_count == 0) 
    {
        cout << "Word count: " << word_count + 1 << endl;
        cout << "Sentence count: " << sentence_count << endl;
        cout << "You did not enter any sentences!" << endl;
    }

When sentence count is 0 but word count is not, you add 1 to the number of words counted. This is what is causing the 'issue' you have described. You do something similar with:

    else 
    {
        word_count++;
        avg_words_per_sentence = word_count / sentence_count;
        cout << "Word count: " << word_count << endl;
        cout << "Sentence count: " << sentence_count << endl;
        cout << "Average words per sentence: " << fixed << setprecision(1) << avg_words_per_sentence << endl;
    }

By adding 1 to word count when you get a nonzero word/sentence count.

I see your intention there, but I think to get your desired behavior, you would just want to account for a word without punctuation as I have added, get rid of the random +1 to word counts, and use integers for comparison as such:

#include <iostream>
#include <iomanip>
#include <cstdlib>
#include <string>
using namespace std;

int main() ///Main
{

    //1. Declaration of variables

    string text;
    int word_count = 0;
    int sentence_count = 0;
    double avg_words_per_sentence;

    //2. Prompt user input

    cout << "Enter a paragraph..." << endl;
    getline(cin, text, '@'); //3. Use getline to read whole paragraph and not first word entered

    //4. Loop to read through text inputted and determine number of words and sentences

    for (int i = 0; i < text.length(); i++) 
    {
        if (text[i] == ' '|| text[i] == '\n')
        {
            word_count++;
        }
        
        else if (text[i] == '.' || text[i] == '!' || text[i] == '?') 
        {
            sentence_count++;
        }
    }
    
    //5. Provides error if there is no text

    if (word_count == 0 && sentence_count == 0) 
    {
        cout << "Word count: " << word_count << endl;
        cout << "Sentence count: " << sentence_count << endl;
        cout << "You did not enter any text!" << endl;
    }
    
    //6. Provides an error if there are no sentences 

    else if (sentence_count == 0) 
    {
        cout << "Word count: " << word_count << endl;
        cout << "Sentence count: " << sentence_count << endl;
        cout << "You did not enter any sentences!" << endl;
    }
    
    //7. Calculates and outputs word/sentence count and average # of words

    else 
    {
        avg_words_per_sentence = word_count / sentence_count;
        cout << "Word count: " << word_count << endl;
        cout << "Sentence count: " << sentence_count << endl;
        cout << "Average words per sentence: " << fixed << setprecision(1) << avg_words_per_sentence << endl;
    }

    return 0;
}

Note that this is still not a perfect approach, as multiple newlines will be counted as words. For anything more advanced, you may want to look into a state machine type approach (keep track of if you have encountered a character before newlines and only count words then, for example). Some sample output from this version is below:

Enter a paragraph...
ttt
@@@
Word count: 1
Sentence count: 0
You did not enter any sentences!
Enter a paragraph...
ttt hehehe.
@@@
Word count: 2
Sentence count: 1
Average words per sentence: 2.0
Enter a paragraph...
ttt heheh
@@@
Word count: 2
Sentence count: 0
You did not enter any sentences!
Enter a paragraph...


@@@
Word count: 2
Sentence count: 0
You did not enter any sentences!