if语句未在字数统计程序中为我的计数器增加价值

Question

I have a java program that reads a txt file and counts the words in that file. I setup my program so the String read from the txt file is saved as an ArrayList, and my variable word contains that ArrayList. The issue with my code is that my if statement does not seem to add a value to my count variable each time it detects space in the word string, it seems to only run the if statement once. How can I make it so the if statement finds a space, adds a +1 to my counter value, removes the space, and looks for the next space in the word variable's string? Here is the code:

       import java.io.*;
    import java.util.*;

    public class FrequencyCounting
    {
        public static void main(String[] args) throws FileNotFoundException
        {       
            // Read-in text from a file and store each word and its
            // frequency (count) in a collection.
            Scanner inputFile = new Scanner(new File("phrases.txt"));
            String word= " ";
            Integer count = 0;

            List<String> ma = new ArrayList<String>();

            while(

inputFile.hasNextLine()) {
            word = word + inputFile.nextLine() + " ";
        }
        ma.add(word);
        System.out.println(ma);
        if(word.contains(" ")) {
            ma.remove(" ");
            count++;
            System.out.println("does contain");
        }
        else {
            System.out.println("does not contain");
        }
        System.out.println(count);
        //System.out.println(ma);
        inputFile.close();

        // Output each word, followed by a tab character, followed by the
        // number of times the word appeared in the file. The words should
        // be in alphabetical order.
        ;  // TODO: Your code goes here.

    }
}

When I execute the program, I get a value of 1 for the variable count and I get a returned string representation of the txt file from my phrases.txt

phrases.txt is :

 my watch fell in the water
time to go to sleep
my time to go visit
watch out for low flying objects
great view from the room
the world is a stage
the force is with you
you are not a jedi yet
an offer you cannot refuse
are you talking to me

Answer 1

Your if statement is not inside any loop, so it will only execute once.

A better approach, which would save a shit ton of runtime, is to read each line like you already do, use the String.split() method to split it on spaces, then add each element of the returned String[] to your list by using the ArrayList.addAll() method (if that one exist, otherwise (optionally, ensure the capacity and) add the elements one by one).

Then count by using the ArrayList.size() method to get the number of elements.

Answer 2

What is your goal here ? Do you just want to read the file and count numbers of words?

Answer 3

You need to use a while loop instead of an if statement that'll just run once. Here's a better way to do what you want to do:

Scanner inputFile = new Scanner(new File("phrases.txt"));
StringBuilder sb = new StringBuilder();
String line;
int totalCount = 0;

while(inputFile.hasNextLine()) {
    line = inputFile.nextLine();
    sb.append(line).append("\n"); // This is more efficient than concatenating strings
    int spacesOnLine = countSpacesOnLine(line);
    totalCount += spacesOnLine;
    // print line and spacesOnLine if you wish to here
}

// print text file
System.out.println(sb.toString());
// print total spaces in file
System.out.println("Total spaces" + totalCount);

inputFile.close();

Then add a method that counts the spaces on a line:

private int countSpacesOnLine(String line) {
    int totalSpaces = 0;
    for(int i = 0; i < line.length(); i++) {
        if (line.charAt(i) == ' ')
            totalSpaces += 1;
    }
    return totalSpaces;
}

Answer 4

您也可以使用以下一种衬垫来实现您的目标：

int words = Files.readAllLines(Paths.get("phrases.txt"), Charset.forName("UTF-8")).stream().mapToInt(string -> string.split(" ").length).sum();

Answer 5

probably I am late, but here is c# simple version:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.IO;

namespace StackOverflowAnswers
{
    class Program
    {
        static void Main(string[] args)
        {

            string contents = File.ReadAllText(@"C:\temp\test.txt");
            var arrayString = contents.Split(' ');
            Console.WriteLine("Number of Words {0}", arrayString.Length);
            Console.ReadLine();
        }
    }
}

Answer 6

Based on the comments in your code :

// Read-in text from a file and store each word and its
// frequency (count) in a collection.
// Output each word, followed by a tab character, followed by the
// number of times the word appeared in the file. The words should
// be in alphabetical order.

My understanding is that you need to store count for every word, rather having a total count of words. For storing count for every word which should be stored itself in alphabetical order, it is better to go with a TreeMap.

public static void main(String[] args) {
    Map<String, Integer> wordMap = new TreeMap<String, Integer>();
    try {
        Scanner inputFile = new Scanner(new File("phrases.txt"));
        while(inputFile.hasNextLine()){
            String line = inputFile.nextLine();
            String[] words = line.split(" ");
            for(int i=0; i<words.length; i++){
                String word = words[i].trim();
                if(word.length()==0){
                    continue;
                }
                int count = 0;
                if(wordMap.containsKey(word)){
                    count = wordMap.get(word);
                }
                count++;
                wordMap.put(word, count);
            }
        }
        inputFile.close();
        for(Entry<String,Integer> entry : wordMap.entrySet()){
            System.out.println(entry.getKey()+"\t"+entry.getValue());
        }
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    }

}