title: PHP foreach loop is being rendered before string concatenation
body: <p>I'm trying to render some components inside of an <code>&lt;article&gt;</code>.</p>
  <p>Hello World component:</p>
  <pre class="lang-php prettyprint-override"><code>//components/HelloWorld.php
  &lt;?php //some comments ?&gt;
  &lt;h1&gt;&lt;?php echo 'Hello World'; ?&gt;&lt;/h1&gt;;
  </code></pre>
  <p>Foo component:</p>
  <pre class="lang-php prettyprint-override"><code>//components/Foo.php
  &lt;?php //some comments ?&gt; 
  &lt;?php echo 'Foo'; ?&gt;;
  </code></pre>
  <p>My Class:</p>
  <pre class="lang-php prettyprint-override"><code>//Render_Content.php
  
  class Render_Content {
  
      public $content_components;
  
      function __construct($args) {
  
          $this-&gt;content_components = $args['content_components'];
  
      }
  
      private function loop_components($components) {
          foreach($components as $component):
              require 'components/' . $component . '.php';
          endforeach;
      }
  
      public function render_content() {
          $rendered_content = '&lt;article&gt;';
          $rendered_content .= $this-&gt;loop_components($this-&gt;content_components);
          $rendered_content .= '&lt;/article&gt;';
  
          echo $rendered_content;
      }
  
  }
  </code></pre>
  <p>My file:</p>
  <pre class="lang-php prettyprint-override"><code>//myfile.php
  
  $args = array(
      'content_components' =&gt; ['HelloWorld', 'Foo']
  );
  $content = new Render_Content($args);
  $content-&gt;render_content();
  </code></pre>
  <p>What I'm expecting to happen is this:</p>
  <pre class="lang-html prettyprint-override"><code>&lt;article&gt;
    &lt;h1&gt;Hello World&lt;/h1&gt;
    &lt;h1&gt;Foo&lt;/h1&gt;
  &lt;/article&gt;
  </code></pre>
  <p>What's happening is this, though:</p>
  <pre class="lang-html prettyprint-override"><code>&lt;h1&gt;Hello World&lt;/h1&gt;
  &lt;h1&gt;Foo&lt;/h1&gt;
  &lt;article&gt;&lt;/article&gt;
  </code></pre>
  <p>What am I doing wrong?</p>
  <p>Thanks in advance for any help.</p>