How do I count words from a file or string object using a nested for loop?

Question

This is for a project, most of it is finished, but I need to be able to count the amount of words there are in a String or file. I have to use a nested for loop, and I have to use a String containing the delimiters for a word. Right now this is what I have:

public static int wordCounter(String text)
{
    String WORDS_GROUP = ",\n ";
    String text= "This is my sample     text";
    int wordCount=0;
    for(int i=0; i<text.length(); i++){
        for(int j=0; j<WORDS_GROUP.length(); j++){
            if(text.charAt(i)==WORDS_GROUP.charAt(j)){
                wordCount++;
            }
        }
    }
}

Answer 1

如果您绝对需要使用嵌套的for循环，则可以让第一个for循环遍历文本中的所有行，第二个（嵌套）for循环遍历每行的所有单词，然后简单地对它们进行计数。

Answer 2

You have increment wordCount only if the last char does not belong to WORDS_GROUP otherwise you end up with more words than you actually have. For example when you find the first space after sample you'll have wordCount is 3 but then comes another space, your algorithm will increment again and this obviously not correct.

You could introduce a new boolean variable which you set to true if you find the first withe space and do the first increment. Then set it to false when you find a non white space Increments happen only when that variable is set to false .

Answer 3

You can maintain a boolean that represents your "state". Are you in a block of spaces (true), or are you in a block of non-spaces (false)?

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

class Ideone {
    public static void main(String[] args) throws java.lang.Exception {
        String WORDS_GROUP = ",\n ";
        String text = "This is my sample     text";
        int wordCount = 0;
        boolean previousCharWasSpace = true;
        for (int i = 0; i < text.length(); i++) {
            boolean thisCharIsASpace = false;
            for (int j = 0; j < WORDS_GROUP.length(); j++) {
                if (text.charAt(i) == WORDS_GROUP.charAt(j)) {
                    previousCharWasSpace = true;
                    thisCharIsASpace = true;
                    break;
                }
                System.out.println("char=" + text.charAt(i) + " j=" + j
                        + " previousCharWasSpace=" + previousCharWasSpace);
            }
            if (!thisCharIsASpace && previousCharWasSpace) {
                wordCount++;
                previousCharWasSpace = false;
                System.out.println("char=" + text.charAt(i)
                        + " previousCharWasSpace=" + previousCharWasSpace
                        + " wordCount=" + wordCount);
            }
        }
        System.out.println("wordCount=" + wordCount);
    }
}

Output:

char=T j=0 previousCharWasSpace=true
char=T j=1 previousCharWasSpace=true
char=T j=2 previousCharWasSpace=true
char=T previousCharWasSpace=false wordCount=1
char=h j=0 previousCharWasSpace=false
char=h j=1 previousCharWasSpace=false
char=h j=2 previousCharWasSpace=false
char=i j=0 previousCharWasSpace=false
char=i j=1 previousCharWasSpace=false
char=i j=2 previousCharWasSpace=false
char=s j=0 previousCharWasSpace=false
char=s j=1 previousCharWasSpace=false
char=s j=2 previousCharWasSpace=false
char=  j=0 previousCharWasSpace=false
char=  j=1 previousCharWasSpace=false
char=i j=0 previousCharWasSpace=true
char=i j=1 previousCharWasSpace=true
char=i j=2 previousCharWasSpace=true
char=i previousCharWasSpace=false wordCount=2
char=s j=0 previousCharWasSpace=false
char=s j=1 previousCharWasSpace=false
char=s j=2 previousCharWasSpace=false
char=  j=0 previousCharWasSpace=false
char=  j=1 previousCharWasSpace=false
char=m j=0 previousCharWasSpace=true
char=m j=1 previousCharWasSpace=true
char=m j=2 previousCharWasSpace=true
char=m previousCharWasSpace=false wordCount=3
char=y j=0 previousCharWasSpace=false
char=y j=1 previousCharWasSpace=false
char=y j=2 previousCharWasSpace=false
char=  j=0 previousCharWasSpace=false
char=  j=1 previousCharWasSpace=false
char=s j=0 previousCharWasSpace=true
char=s j=1 previousCharWasSpace=true
char=s j=2 previousCharWasSpace=true
char=s previousCharWasSpace=false wordCount=4
char=a j=0 previousCharWasSpace=false
char=a j=1 previousCharWasSpace=false
char=a j=2 previousCharWasSpace=false
char=m j=0 previousCharWasSpace=false
char=m j=1 previousCharWasSpace=false
char=m j=2 previousCharWasSpace=false
char=p j=0 previousCharWasSpace=false
char=p j=1 previousCharWasSpace=false
char=p j=2 previousCharWasSpace=false
char=l j=0 previousCharWasSpace=false
char=l j=1 previousCharWasSpace=false
char=l j=2 previousCharWasSpace=false
char=e j=0 previousCharWasSpace=false
char=e j=1 previousCharWasSpace=false
char=e j=2 previousCharWasSpace=false
char=  j=0 previousCharWasSpace=false
char=  j=1 previousCharWasSpace=false
char=  j=0 previousCharWasSpace=true
char=  j=1 previousCharWasSpace=true
char=  j=0 previousCharWasSpace=true
char=  j=1 previousCharWasSpace=true
char=  j=0 previousCharWasSpace=true
char=  j=1 previousCharWasSpace=true
char=  j=0 previousCharWasSpace=true
char=  j=1 previousCharWasSpace=true
char=t j=0 previousCharWasSpace=true
char=t j=1 previousCharWasSpace=true
char=t j=2 previousCharWasSpace=true
char=t previousCharWasSpace=false wordCount=5
char=e j=0 previousCharWasSpace=false
char=e j=1 previousCharWasSpace=false
char=e j=2 previousCharWasSpace=false
char=x j=0 previousCharWasSpace=false
char=x j=1 previousCharWasSpace=false
char=x j=2 previousCharWasSpace=false
char=t j=0 previousCharWasSpace=false
char=t j=1 previousCharWasSpace=false
char=t j=2 previousCharWasSpace=false
wordCount=5

You can play with this here: http://ideone.com/ASEjwB