"WordPairs" I'm trying to compare 2 words in an ArrayList in Java

Question

I'm trying to get the number of matched words in an ArrayList in my Java program

This is the whole thing: The problem is with the numMatch class:

import java.util.*;
    
public class WordPairsList {
    
    private ArrayList<WordPair> allPairs;
    
    public WordPairsList(String[] words)
    {
        allPairs = new ArrayList<WordPair>();
             
        for (int i = 0; i < words.length - 1; i++){
            for (int j = i + 1; j < words.length; j++){
                if (j == i){
                    allPairs.add( new WordPair(words[i], words[j]));
                }
            }
        }
    }
    
    public int numMatches() {
    
             /* in here I need to have a for loop that goes through the ArrayList allPairs and for
    each WordPair in allPairs, it checks to see if its first word (using the getFirst() method)
    equals the second word (using the getSecond() method). If there is a match, it increments a
    counter which it returns at the end of the method. To test this method, add another “there” into
    the words array and then uncomment the call to numMatches().
    */
        return 0;
    }
         
    public String getFirst() {
        return allPairs.getFirst();
    }

    public String getSecond() {
        return allPairs.getSecond();
    }
    
    public String toString() {
        return allPairs.toString();
    }
    
    public static void main(String[] args) {
         String[] words = {"Hi", "there", "Tyler", "Sam"};
         WordPairsList list = new WordPairsList(words);
         System.out.println(list);
         //For second part below, uncomment this test:
         System.out.println("The number of matched pairs is: " + list.numMatches());
    }
}
    
class WordPair {
    private String word1;
    private String word2;
    
    public WordPair(String w1, String w2) {
        word1 = w1;
        word2 = w2;
    }

    public String getFirst() {
        return word1;
    }

    public String getSecond() {
        return word2;
    }

    public String toString() {
        return "(" + word1 + ", " + word2 + ")";
    }
}

So I need help with how to call the getFirst() and getSecond() Methods and how to compare them using a for loop! I also don't know how to set a counter to count how many similar words are there! can you please help me!

Thanks!

question from:https://stackoverflow.com/questions/65854781/wordpairs-im-trying-to-compare-2-words-in-an-arraylist-in-java

Answer 1

Not sure if this is what you need, but this will iterate over the list of wordpairs and count them:

import java.util.*;

class WordPairsList {
    //can be final and List interface
    private final List<WordPair> allPairs;

    public WordPairsList(String[] words)
    {
        allPairs = new ArrayList<>();
        //As I understood it you want to take the input and generate word pair from every two words?
        for (int i = 0; i < words.length - 1; i += 2){
            allPairs.add( new WordPair(words[i], words[i+1]));
        }
    }

    public int numMatches() {
        //initialize your count variable
        int count = 0;
        //loop over your word pairs (if your java version doesn't support this, use a for(int i = 0....) loop as seen above
        for (WordPair wordPair : allPairs) {
            ///debug print
            System.out.println("Testing: "+ wordPair.toString());
            //check if pair.getfirst equals pair.getsecond
            if(wordPair.getFirst().equals(wordPair.getSecond())){
                //increase count
                count += 1;
            }
        }
        //return count
        return count;
    }

    public static void main(String[] args) {
        String[] words = {"Hi", "there", "Tyler", "Sam", "Bob", "Bob"};
        WordPairsList list = new WordPairsList(words);
        System.out.println("The number of matched pairs is: " + list.numMatches());
    }
}

class WordPair {
    private final String word1;
    private final String word2;

    public WordPair(String w1, String w2) {
        word1 = w1;
        word2 = w2;
    }

    public String getFirst() {
        return word1;
    }

    public String getSecond() {
        return word2;
    }

    public String toString() {
        return "(" + word1 + ", " + word2 + ")";
    }
}