title: I want to know everything about "?" value of action attribute
body: <p>I wanted to know everything about the "?" of action value of a form. As you see in the code below, We have a form (placed in </p>
  
  <p>a php template) that sends user input to be put in the database with the value of "?" for the action attribute:</p>
  
  <pre><code>&lt;form action="?" method="post"&gt;
  &lt;div&gt;
  &lt;label for="joketext"&gt;Type your joke here:&lt;/label&gt;
  &lt;textarea id="joketext" name="joketext" rows="3" cols="40"&gt;
  &lt;/textarea&gt;
  &lt;/div&gt;
  &lt;div&gt;&lt;input type="submit" value="Add"&gt;&lt;/div&gt;
  &lt;/form&gt;
  </code></pre>
  
  <p>We have also another template that shows the data stored in our database and as you see in the code below, this template has </p>
  
  <p>a section with a link so that by clicking that link users can add data (jokes) in our database:</p>
  
  <pre><code>&lt;body&gt;
  &lt;p&gt;&lt;a href="?addjoke"&gt;Add your own joke&lt;/a&gt;&lt;/p&gt;
  &lt;p&gt;Here are all the jokes in the database:&lt;/p&gt;
  &lt;?php foreach ($jokes as $joke): ?&gt;
  &lt;blockquote&gt;
  &lt;p&gt;&lt;?php echo htmlspecialchars($joke, ENT_QUOTES, 'UTF-8');
  ?&gt;
  &lt;/p&gt;
  &lt;/blockquote&gt;
  &lt;?php endforeach; ?&gt;
  &lt;/body&gt;
  </code></pre>
  
  <p>My first question is why we set the value of href attribute to be "?addjoke"? I mean what is the job of "?" in "?addjoke"?</p>
  
  <p>Well, Another question is: We have an if statement in our index.php file that is like this:</p>
  
  <pre><code>if (isset($_GET['addjoke']))
  {
  include 'form.html.php';
  exit();
  }
  </code></pre>
  
  <p>I can't get the idea of "addjoke" variable in our $_GET array. I mean I know exactly what the $_GET array does but I can't </p>
  
  <p>understand the whole idea of using "addjoke" variable. I mean what is exactly "addjoke" doing here?</p>
  
  <p>So obviously I have a lot of problems with understanding the "?" character in URLs and I need your help :) All I know about </p>
  
  <p>"?" is that this value is used when we need to point to the same page we're on. right?</p>
  
  <p>I have other questions too, but that questions are kept to be asked another time ;) Thank you so much in advance.</p>