在 Java 中使用 while 循环来计算句子

Question

UPDATE:
Figured it out with the help of everyone and some friends! I needed to catch the \\n character in the string variable as well as the empty string. Thank you to everyone who commented and helped!

This is for an assignment for Intro to Java, we haven't gotten to methods yet and when googling for help that was the only thing popping up so I figured I might as well attempt asking myself.

Thanks in advance!

For our project we have to create a program that calculates the FRI of some simple texts and I'm having two problems.

This first problem is that while counting sentences from a file using a Scanner object and a while loop my count is always wrong by +1. I can see in the console print out that it's counting the empty string, the \\n that prints out (I'm printing to the console so I can see what the variable is being given, not because it's required) even though I have it set to only increase my accumulating variable if my string isn't empty.

Any help would be appreciated! I'm not sure what parts of my code are needed, but...

/* Count Sentences */
//Scanner object to read inputText
Scanner countSentences = new Scanner(inputText);

// While loop to count sentences
while(countSentences.hasNext()){
    String sentence = countSentences.useDelimiter(SENTENCE_DELIMITERS).next();
    System.out.println(sentence);
    if(sentence.compareTo("") != 0){
        numSentences++;
    }
}

...is the bit where the sentence counting takes place.

Thanks again!

Entire code! Edit:

DESCRIPTION:
A program to calculate the Flesch Readability Index of a text

public class Readability {

    public static void main(String[] args) throws IOException{
        final double FIRST_CONSTANT = -1.015;               //First constant of FRI formula
        final double SECOND_CONSTANT = 84.6;                //Second constant of FRI formula
        final double THIRD_COSTANT = 206.835;               //Third constant of FRI formula
        final String SENTENCE_DELIMITERS = "[.:;?!]";       //Sentence delimiters
        final String WORD_DELIMITERS = "[.:;?! ,\t,\n]";    //Word delimiters
        
        int numSentences = 0;                               //Number of sentences in inputText
        int numWords = 0;                                   //Number of words in inputText
        int numSyllables = 0;                               //Number of syllables in each word in inputText
        
        String standardText = "This is just a test.";       //Standard Text for testing
        String inputText = "";                              //Holds the text being tested currently
        
        /* Ask user if they want to run a text analysis */
        int choice = JOptionPane.showConfirmDialog(null, "Do you want to run a text analysis?", "Start the Flesch Reading Ease Test", JOptionPane.YES_NO_OPTION);
        
        /* Message Displayed if 'No' selected, and program exits */
        if(choice == JOptionPane.NO_OPTION) {
            JOptionPane.showMessageDialog(null, "The program exits. Good Bye!");
            System.exit(0);
        }
        
        /* If user selects 'Yes' */
        // Ask user if they have a text file or wish to use the standard text
        choice = JOptionPane.showConfirmDialog(null, "Answer \"Yes\" if you want to read the text from a file!\nAnswer \"No\" if you want a test run on a standard text.", "Select the input!", JOptionPane.YES_NO_OPTION);
        
            /* If user selects 'Yes' */
            if(choice == JOptionPane.YES_OPTION){
                // Ask user for filename
                String inputFileName = JOptionPane.showInputDialog("Enter input file name with extension!\nInclude the path if file is not in the project folder!");
                
                    // User presses cancel, set inputText to standardText 
                    if(inputFileName == null){
                        inputText = standardText;
                    }
                    
                    // User presses enter, create file object using user input as filename
                    else{
                        File file = new File(inputFileName);
                    
                    // Check if file exists, if file exists create scanner object to read text from file
                    if(file.exists()){
                        Scanner readFile = new Scanner(file);
                        
                        // Read the file line by line and collect the concatenated lines in the variable inputText
                        while(readFile.hasNext()){
                            String fileSentences = readFile.nextLine();
                            inputText += fileSentences + "\n";
                        }
                    }
                    // If file doesn't exist, set inputText to the standardText
                    else {
                        inputText = standardText;
                    }
                    }
            }
        
            /* If user selects 'No' */
            else{
                inputText = standardText;
            }    
        
            /* Count Sentences */
            //Scanner object to read inputText
            Scanner countSentences = new Scanner(inputText);
            
            // While loop to count sentences
            while(countSentences.hasNext()){
                String sentence = countSentences.useDelimiter(SENTENCE_DELIMITERS).next();
                System.out.println(sentence);
                if(sentence.length() != 0){
                    numSentences++;
                }
                System.out.println(numSentences); //This println prints the correct number to the console
            }
            System.out.println(numSentences);  //This println prints +1
            
            //Close countSentences scanner
            countSentences.close();
            
            /* Count Words */
            //Scanner object to read inputText
            Scanner countWords = new Scanner(inputText);
            
            // While loop to count words and increment syllable count per word (rule #3: each word has at least one syllable)
            while(countWords.hasNext()){
                String word = countWords.useDelimiter(WORD_DELIMITERS).next();
                
                if(word.compareTo("") != 0){
                    numWords++;
                    //numSyllables++;
                }
                
                // For loop to count syllables as each word is read
                for(int k = 0; k < word.length(); k++){
                    char letter = word.charAt(k);
                    
                    
                }
            }
            
    //Test//
    System.out.println(inputText);
    System.out.println(numSentences);
    System.out.println(numWords);
    System.out.println(numSyllables);
    }
    
}

Answer 1

Here is the working program. It gave me result as 2.

import java.util.Scanner;
    public class Scannerd {

      public static String inputText = "What!? That is awful!";

      public static String SENTENCE_DELIMITERS = "[.:;?!]";

            public static void main(String... arg) {
              int numSentences = 0;

              Scanner countSentences = new Scanner(inputText);

              // While loop to count sentences
              while (countSentences.hasNext()) {
                String sentence = countSentences.useDelimiter(SENTENCE_DELIMITERS).next();
                System.out.println(sentence);
                if(sentence.compareTo("") != 0){
                  numSentences++;
                }

              }
              System.out.println("#ofSentences"+numSentences);
            }
    }

Answer 2

Looks like it uses the default delimiter in the beginning since the custom delimiter is used inside the loop. Try this.

import java.util.Scanner;
public class TestScanner {

  public static String inputText = "What!? That is awful!";

  public static String SENTENCE_DELIMITERS = "[.:;?!]";

        public static void main(String... arg) {
          int numSentences = 0;

          Scanner countSentences = new Scanner(inputText);
          countSentences.useDelimiter(SENTENCE_DELIMITERS);
          // While loop to count sentences
          while (countSentences.hasNext()) {
            //String sentence = countSentences.useDelimiter(SENTENCE_DELIMITERS).next();
              String sentence = countSentences.next();
            System.out.println(sentence);
            if(sentence.compareTo("") != 0){
              numSentences++;
            }

          }
          System.out.println("#ofSentences"+numSentences);
        }
}

Answer 3

Try using hasNextLine() and nextLine() methods.

/* Count Sentences */
//Scanner object to read inputText
Scanner countSentences = new Scanner(inputText);

// While loop to count sentences
while(countSentences.hasNextLine()){
    String sentence = countSentences.useDelimiter(SENTENCE_DELIMITERS).nextLine();
    System.out.println(sentence);
    if(sentence.compareTo("") != 0){
        numSentences++;
    }
}