使用 Scanner.next() 方法计算单词

Question

I am currently working on a method that has to return the number of newline characters, words, and characters of a string in an int[] array. I am confused on how count the number of times the Scanner.next() method runs. I have tried to use an if statement like this:

if (!(in.next() == (""))) { words++; }

but I get java.util.NoSuchElementException. How would I get around the NoSuchElementException and count the tokens instead of returning them? Here is what I have so far:

import java.util.Scanner;

public class WordCount {

/**
 * Scans a string and returns the # of newline characters, words, and
 * characters in an array object.
 * 
 * @param text string to be scanned
 * @return # of newline characters, words, and characters
 */
public static int[] analyze(String text) {
    // Variables declared
    Scanner in = new Scanner(text);
    int[] values = new int[3];
    int line = 0;
    int words = 0;
    int characters = 0;

    // Checks string for # of newlines, chars, and words
    for (int i = 0; i < text.length(); i++) {
        char n = text.charAt(i);

        if (n == '\n') {
            line++;
        }
        if (in.hasNext()) {
            characters++;
        }

        //this is where I think the word count statement should go

    }
    values[0] = line;
    values[1] = words;
    values[2] = characters;
    return values;
}

public static void main(String[] args) {
    analyze("This is\n a test sentence.");
}

The test should return an array of {1, 5, 25}.

Answer 1

For checking the amount of word in a string, you will need to check if the next character is a letter. At the same time, you will need a condition to check if it is end of the word.

boolean isEndWord = false;
// Checks string for # of newlines, chars, and words
for (int i = 0; i < text.length(); i++) {
   char n = text.charAt(i);
   if ((!Character.isLetter(n))&&isEndWord == true) {
      words++;
      isEndWord = false;
   }
   if (n == ' ') {
      isEndWord = true;
   }
   if (n == '\n') {
       line++;
       isEndWord = true;
   }
   if (in.hasNext()) {
       characters++;
   }
}

You can used the boolean isEndWord to trigger whenever the word ends.