如何计算单词（包括空格）？

Question

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class MyFirstProject {

  public static void main(String argv[]) throws IOException {

    //This line will create a buffered reader that reads from the system input using an input stream reader
    BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));
    //input will contain the first line of input from the user   
    /**
     * This asks a question.
     */
    System.out.println("What is your input?");
    String input = bufferedReader.readLine();
    /**
     * This returns a valediction or the input.
     */
    if (input.equals("exit")) {
        System.out.println("GOODBYE!");
    }
    else {
        System.out.println(input);
    }


    }


/**
 * This counts the number of words (including spaces) in a string.
 * @param words The user input.
 * @return The number of words in a string.
 */
public static String numberOfWords(String words) {
  int count = 0;
  if (words.length() == 1) {
      count++;
      return (String.valueOf(count) + "word");
  }
  if (words.length() > 1) {
      for (int i = 0; i <= words.length(); i++) {
          if (words.charAt(i) == ' ') {
              count++;
          }
      }
      return (String.valueOf(count) + "words");
  }
  else {
      return (String.valueOf(count) + "words");
  }
}
}

我的问题很简单。我很难理解为什么我的代码不会返回输入中的单词数。输出应该是这样的，例如，如果用户在控制台上的输入是“hello world”：

您的意见是什么？
你好世界
你好世界
3 个字
1 个空间
11 个字符

Answer 1

首先，为了能够得到函数numberOfWords的计算结果，你需要用你的输入调用它，见代码

接下来更喜欢Scanner而不是BufferedReader + InputStreamReader，语法更简单

public static void main(String argv[]) {

    Scanner sc = new Scanner(System.in);

    System.out.println("What is your input?");
    String input = sc.nextLine();                   // change to Scanner

    if (input.equals("exit")) {
        System.out.println("GOODBYE!");
    } else {
        System.out.println(input);
        System.out.println(numberOfWords(input));  // add method call
    }
}

我还提供了一种更简单的方法来实现你的东西：

public static String numberOfWords(String words) {
    int nbWord = words.split("\\s").length;
    int nbSpaces = nbWord - 1;
    return (nbWord + nbSpaces) + " words\n" + nbSpaces + " spaces\n" + words.length() + " characters";
}

words.split("\\s") 分割空格并创建一个单词数组，其长度为空格数

Answer 2

使用 split 并将结果分配给数组将使您能够获得所需的所有信息，如您所见，我首先 trim 因为我们假设只有单词之间的空白。

words = words.trim();
      String tokens[] = words.split(" ");

下面是使用此方法的工作示例：

 words = words.trim();
      String tokens[] = words.split(" ");
      int chars =0;
      int wordsN =0;
      int whitespace = 0;
      for(String s : tokens){
          chars+=s.length();
          wordsN++;       
      }
      whitespace = wordsN-1;
      chars += whitespace;

      System.out.println(chars);
      System.out.println(wordsN);
      System.out.println(whitespace);

Answer 3

这里可以使用拆分功能

            String input = "Hello World";
    String w[]=input.split(" ");
    int words=w.length;
    int l=input.length();
    System.out.println("characters "+l);
    System.out.println("words "+words);
    System.out.println("spaces "+(words-1));

输出：字符 11 词 2 空格 1

Answer 4

你永远不会在你的 main 方法中调用你的 numberOfWords 函数。

试试这个：

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class MyFirstProject {

  public static void main(String argv[]) throws IOException {

    //This line will create a buffered reader that reads from the system input using an input stream reader
    BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));
    //input will contain the first line of input from the user   
    /**
     * This asks a question.
     */
    System.out.println("What is your input?");
    String input = bufferedReader.readLine();
    /**
     * This returns a valediction or the input.
     */
    if (input.equals("exit")) {
        System.out.println("GOODBYE!");
    }
    else {
        //****** HERE'S IS CHANGE! ********
        System.out.println(numberOfWords(input));
    }


    }


/**
 * This counts the number of words (including spaces) in a string.
 * @param words The user input.
 * @return The number of words in a string.
 */
public static String numberOfWords(String words) {
  int count = 0;
  if (words.length() == 1) {
      count++;
      return (String.valueOf(count) + "word");
  }
  if (words.length() > 1) {
      for (int i = 0; i <= words.length(); i++) {
          if (words.charAt(i) == ' ') {
              count++;
          }
      }
      return (String.valueOf(count) + "words");
  }
  else {
      return (String.valueOf(count) + "words");
  }
}
}