title: Why am I getting NullPointerException on my "plain1.findPosition(iMsg)"?
body: <p>First Class which is giving me the error. I'm to make an array with the letters A-Z, and then have the user input the keys which it takes and compares each character's position in the array of the key with the position of a user inputted string</p>
  <pre><code>import java.util.*;
      public class Encrypt{
          private Square plain1;
          private Square plain2;
          private Square Encrypt1;
          private Square Encrypt2;
  
      public Encryption(String key1, String key2) {
          Square plain1 = new Square();
          Square plain2 = new Square();
          Square Encrypt1= new Square(key1);
          Square Encrypt2= new Square(key2);
      } 
  
  
      public String encrypt(String msg) {
          String EmpS = &quot;&quot;;
          String STR = &quot;&quot;;
  
          for(int i = 0; i &lt; message.length(); i+=2){
              char iMsg = message.charAt(i);
              char iMsg2 = message.charAt(i+1);
              int[] posRay = plain1.findPosition(iMsg);
              int[] posRay2 = plain2.findPosition(iMsg2);
              String answer = &quot;&quot; + Encrypt1.getChar(posRay[0], posRay2[1]);
              String Combined = &quot;&quot; + answer;
              String answer2 = &quot;&quot; + Encrypt2.getChar(posRay2[0], posRay[1]);
              String Combined2 = &quot;&quot; + answer2;
  
              String BothCom = Combined + Combined2;
              STR = STR.concat(BothCom);
  
          return STR;
          }
          return STR;
      } 
  </code></pre>
  <p>2nd class that is responsible for the array</p>
  <pre><code>public class Square {
      private char[][] matrix;
  public Square() {
          arr= new char[5][5];
          int ascii= 65;
          for (int i = 0; i &lt; 5; i++){
              for(int j = 0; j &lt; 5; j++){
                  arr[i][j] = (char) ascii;
                  ascii++;
                  }
              }
          }
  }
  public int[] findPosition(char Chart) {
          int[] position= new int[2];
          position[0] = -1;
          popositions[1] = -1;
          for (int i = 0; i &lt; 5; i++){
              for (int j = 0; i &lt; 5; j++){
                  if(matrix[i][j] == Chart){
                  posistion[0] = i;
                  position[1] = j;
                  return position;
                  }
              }
          }
  </code></pre>
  <p>I'm getting this as an error (everything else works), what's the issue?:</p>
  <pre><code>Exception in thread &quot;main&quot; java.lang.NullPointerException: Cannot invoke &quot;Square.getPos(char)&quot; because &quot;this.plain1&quot; is null
          at findPosition.encrypt(Encrypt.java:45)
          at IO.printResults(IO.java:101)
          at Test.main(Proj8.java:26)
  </code></pre>