title: The operator is undefined
body: <p>I just tried to make a simple class that lets me figure out the length of a file:</p>
  
  <pre><code>public class Size {
  
      long s = 0;
      int a;
  
      public static void main(String[]args){
          new Size();
      }
  
      Size(){
  
          try{
          FileInputStream str = new FileInputStream("E:/Eclipse/Resources/smile.jpg");
  
          while(a != null){
              s++;
          }
          }catch (IOException e){
              e.printStackTrace();
          }
  
      }
  
  
  }
  </code></pre>
  
  <p>I run into a problem with</p>
  
  <pre><code>while(a != null)
  </code></pre>
  
  <p>I get the Error:</p>
  
  <blockquote>
    <p>The operator != is undefined for the argument type(s) int, null</p>
  </blockquote>
  
  <p>Any ideas why it's blocking the condition?</p>