Java字数统计

Question

I am just starting out in Java so I appreciate your patience. Anyways, I am writing a word count program as you can tell by the title, I am stuck at the numWords function below the for loop, I am not sure what I should set it equal to. If someone could set me in the right direction that would be awesome. Thank you. Here is all of my code thus far, let me know if I not specific enough in what I am asking, this is my first post. Thanks again.

import java.util.Scanner;
public class  WCount {

    public static void main (String[] args) {
        Scanner stdin = new Scanner(System.in);

        String [] wordArray = new String [10000];
        int [] wordCount = new int [10000];
        int numWords = 0;

        while(stdin.hasNextLine()){
            String s = stdin.nextLine();
            String [] words = s.replaceAll("[^a-zA-Z ]", "").toLowerCase().split("\\s\
+");
            for(int i = 0; i < words.length; i++){
                numWords = 0;
            }
        }
    }
}

Answer 1

If your code is intended to just count words, then you don't need to iterate through the words array at all. In other words, replace your for loop with just:

numWords += words.length;

Most likely a simpler approach would be to look for sequences of alpha characters:

Matcher wordMatch = Pattern.compile("\\w+").matcher(); 
while (wordMatch.find())
    numWords++;

If you need to do something with the words (such as store them in a map to a count) then this approach will make that simpler:

Map<String,Integer> wordCount = new HashMap<>();
Matcher wordMatch = Pattern.compile("\\w+").matcher(); 

while (wordMatch.find()) {
    String word = wordMatch.group();
    int count = wordCount.getOrDefault(word, 0);
    wordCount.put(word, count + 1);
}

Answer 2

Don't worry. We were all beginners once.

First of all, you don't need to do the loop because "length" attribute already has it. But, if you want to practice with loops is so easy as increasing the counter each time the iterator advances and that's it.

numWords++;

Answer 3

Hint: Read the input

String sentence = stdin.nextLine();

Split the string

String [] words = sentence.split(" ");

Number of words in a sentence

System.out.println("number of words in a sentence are " + words.length);

You mentioned in comments that you would also like to print the line in alphabetical order. For that Java got you covered:

Arrays.sort(words);

Answer 4

计算String String phrase中单词数量的最好方法就是使用String方法split String[] words = phrase.split(" ")从字符串数组中获取一个String数组，并将其本身作为参数，这是最好的方法将返回一个包含每个单词的String数组，然后您可以简单地检查它的长度words.length ，这将为您提供确切的数字。