title: Wordpress get_the_ID() returns nothing but get_the_title() returns title?
body: <p>I'm struggling with wordpress templates.  In one of my theme templates I have the following lines</p>
  
  <pre><code>&lt;?php
  echo get_the_ID(); // displays nothing
  echo get_the_title(); // displays "Hello World! this is title"
  ?&gt;
  </code></pre>
  
  <p>Why does the get_the_ID() return nothing ?  I want the page id of the current page I'm on.</p>