title: How to declare a constant in Java?
body: <p>We always write: </p>
  
  <pre><code>public static final int A = 0;  
  </code></pre>
  
  <p>Question:  </p>
  
  <ol>
  <li>Is <code>static final</code> the only way to declare a <strong>constant</strong> in a class?  </li>
  <li>If I write <code>public final int A = 0;</code> instead, is <code>A</code> still a <strong>constant</strong> or just an <strong>instance field</strong>?  </li>
  <li>What is an <strong>instance variable</strong>? What's the difference between an <strong>instance variable</strong> and an <strong>instance field</strong>?</li>
  </ol>