title: Program to find and count repeated words in a text. The strings are writen wrong?
body: <p>I did wrote a code that gets a text file as input, then the program makes to equal String arrays with the text so the words can be compared and find + count the unique and repeated words. The program becomes compiled successfully but if I try to execute it so I get the problem: Exception in thread"main"java.lang.NullPointerException...java:52.
  The problem must be in the way I declare the strings. How should I write them instead?
  Thanks!</p>
  
  <pre><code>import java.util.*;
  
  class TextAnalyze{
  public static void main(String[] args){
  In read = new In ("text1.txt"); //input *.txt file
  
      int tWords = 0; // counter, total words in the text file
      int unW = 0; //counter UNIQUE words in the text file
      String[] word = new String[31000]; //array with all the words
      String[] word2 = new String[31000]; // array with all the words, used to compare
      //String uniqueWords[] = new String[31000]; //array with the unique words
      //int numberuniqueWords[] = new int [31000];
  
      while(read.endOfFile() == false) {
  
          word[tWords] = read.inWord();
          word2[tWords] = word[tWords];
          tWords++;
  
      }
  
      int totalWords = word.length;
      int totalWords2 = word2.length;
  
      List&lt;String&gt; uniqueWords = new ArrayList&lt;&gt;();
  
      for (int i = 0; i &lt; totalWords; i++) { // loop of the first array list
          boolean unique = true;
  
          for (int j = 0; j &lt; totalWords2; j++) { // second loop where the
                                          // words are being compared
              if (word[i].equals(word2[j])) {
                  //we find two equals strings, it not unique
                  unique = false;
                  break;
              }
          }
  
          //if it remains unique there wasn't equals
          if (unique) {
              uniqueWords.add(word[i]);
          }
      }
  
      for (String s : uniqueWords) {
          System.out.println(s);
      }
  
  }
  </code></pre>
  
  <p>}</p>