title: PHP making difference between get with and without value
body: <p>Good day,</p>
  <p>I would like to know if there is any function for making the difference between this:</p>
  <pre><code>?param=
  </code></pre>
  <p>and this:</p>
  <pre><code>?param
  </code></pre>
  <p>Because I would like my script to detect if value is empty (first example), or if it's not given (second example).</p>
  <p>I made a test with the following functions but I could not find what I want:</p>
  <pre><code>if( isset( $_GET['param'] ) ) {
      echo '&lt;div&gt;isset&lt;/div&gt;';
      
      if( empty( $_GET['param'] ) ) {
          echo '&lt;div&gt;empty&lt;/div&gt;';
      } else {
          echo '&lt;div&gt;not empty&lt;/div&gt;';
      }
      
      if( is_null( $_GET['param'] ) ) {
          echo '&lt;div&gt;null&lt;/div&gt;';
      } else {
          echo '&lt;div&gt;not null&lt;/div&gt;';
      }
      
      if( defined( $_GET['param'] ) ) {
          echo '&lt;div&gt;defined&lt;/div&gt;';
      } else {
          echo '&lt;div&gt;undefined&lt;/div&gt;';
      }
  } else {
      echo '&lt;div&gt;not set&lt;/div&gt;';
  }
  </code></pre>
  <p>Any idea? Thank you in advance.</p>
  <p><strong>EDIT</strong></p>
  <p>Solution:</p>
  <pre><code>( strpos( '?'.$_SERVER['QUERY_STRING'], '?get=' ) !== false ) || ( strpos( '?'.$_SERVER['QUERY_STRING'], '&amp;get=' ) !== false )
  </code></pre>