arraylist split("whitespace") 并计算单词数

Question

so I want to count the number of words in my ArrayList , currently I read lines from a file and saved those lines to the ArrayList .
The file has

word    definition
a       alpha
b       bravo
c       charlie
d       delta
e       echo
f       foxtrot

so when I do arraylist.size() it prints 7. but I want to count the number of words.

my code:

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;

public class WarmUp {
    public static void main(String[] args) {
        BufferedReader br = null;
        String line = null;
        ArrayList<String> elements = new ArrayList<String>();

        try {
            br = new BufferedReader(new FileReader("src/dictionary.txt"));
            while((line=br.readLine()) != null) {
                elements.add(line);
            }
        }
        catch(IOException e) {
            e.printStackTrace();
        }       
    }
}

I think I can use split method so I thought this is the way

ArrayList<String> moreElements = new ArrayList<String>();

for(int i=0; i < elements.size(); i++) {
    String e = elements.get(i);
    moreElements.addAll(e.split(" "));

}

then call moreElements.size() but I'm doing something wrong...

Answer 1

The method addAll() expects a list but split() returns an array.
You must use Arrays.asList() to convert the array to a list.
Also you must split by multiple spaces.
Change to this:

moreElements.addAll(Arrays.asList(e.split("\\s+")));

Answer 2

If you use Java 8 or higher you can use (assuming your List is called elements ):

int count = elements.stream().mapToInt(x -> x.split("\\s+").length).sum();

Solution with a loop:

int count = 0;
for(String line : elements) {
  String[] tmp = line.split("\\s+"); //split on one or more spaces
  count += tmp.length;
}