title: need some beginner guide about classes
body: <p>I just started learning Java and I have a problem with defining a class.
  I defined some variables in a class, but everywhere I wrote a command for printing a value of a string (or other variables) I got an error that says "cannot find symbol". Does that mean I can't use a print command in a class? Can you do a favor and simply explain me what to do?</p>
  
  <p>Here is my codes (it's just for testing):</p>
  
  <pre><code>class Variable {
      int m = 15;
      boolean myb = true;
      double mon = 2.4;
  }
  </code></pre>