title: isset() evaluates to true even when the textfields are empty. Why is that?
body: <p>The first snippet takes data from the two text fields and sends to <code>action script.php</code>. The problem is both the <code>if</code> statements evaluate to true even if I do not enter anything in the text fields. Why is that ?</p>
  
  <pre><code>try.php
  
  &lt;form method='get' action='./action_script.php'&gt;
          &lt;input type="text" id="text_first" name="text_first" /&gt; &lt;br /&gt;
          &lt;input type="text" id="text_second" name="text_second"/&gt; &lt;br /&gt;
          &lt;input type="submit" id="submit" /&gt;
  &lt;/form&gt;
  </code></pre>
  
  <hr>
  
  <pre><code>action_script.php
  
  &lt;?php
  
    if(isset($_GET['text_first'])) {
          echo "Data from the first text field : {$_GET['text_first']} &lt;br&gt;";
    }
    if(isset($_GET['text_second'])) {
          echo "Data from the second text field : {$_GET['text_second']} &lt;br&gt;";
    }
  
    echo "After the if statement &lt;br /&gt;";
  </code></pre>