dictionary.java

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import java.io.*;

/**
 * This class models a dictionary
 *
 * @author author name
 * @version 1.0.0
 */
public class Dictionary {

    /* Standard output stream */
    private static PrintWriter  stdOut =
        new  PrintWriter(System.out, true);

    /* Standard error stream */
    private static PrintWriter  stdErr =
        new  PrintWriter(System.err, true);

    /* Initial size of the array */
    private static final int INITIAL_SIZE = 5;

    /* Words in the dictionary */
    private String[] words;

    /* Indicates the next available location in the array */
    private int nextIndex;

    /**
     * Tests the implementation of class <code>Dictionary</code>.
     *
     * @param args  not used.
     */
    public static void main(String[] args) {

        Dictionary dictionary = new Dictionary();

        String[] knownWords = {"desk", "computer", "house", "dog",
                               "cat", "world", "book", "money", "river", "paper",
                               "coffee"};
        String[] unknownWords = {"maison", "haus", "casa"};

        for (int i = 0; i < knownWords.length; i++) {
            dictionary.addWord(knownWords[i]);
        }
        for (int i = 0; i < knownWords.length; i++) {
            if (! dictionary.hasWord(knownWords[i])) {
                stdErr.println("** Test failure, " +
                               "word not found in the dictionary: " +
                               knownWords[i]);
            }
        }
        for (int i = 0; i < unknownWords.length; i++) {
            if (dictionary.hasWord(unknownWords[i])) {
                stdErr.println("** Test failure, " +
                               "non dictionary word found in dictionary: "
                               + unknownWords[i]);
            }
        }

        stdOut.println("done");
    }

    /**
     * Creates an empty dictionary.
     */
    public Dictionary()  {

        words = new String[INITIAL_SIZE];
        nextIndex = 0;
    }

    /**
     * Adds a new word to this dictionary.
     *
     * @param word  the  word to be added.
     */
    public void addWord(String word)  {

        if (nextIndex >= words.length) {

            // creates a new array, which is twice the size
            // of the current array
            String[] biggerWords = new String[2 * words.length];

            // copies the contents of the current array
            // into the new array
            for (int i = 0; i < words.length; i++) {
                biggerWords[i] = words[i];
            }
            words = biggerWords;
        }
        words[nextIndex] = word;
        ++nextIndex;
    }

    /**
     * Returns <code>true</code> if the specified word is part of
     * this dictionary.
     *
     * @param word  the word to be looked for.
     * @return <code>true</code> if the specified word is part of
     *         this dictionary; <code>false</code> otherwise.
     */
    public boolean hasWord(String word)  {

        for (int i = 0; i < nextIndex; i++) {
            if (words[i].equals(word)) {
                return true;
            }
        }
        return false;
    }
}