How do I check the value of a Boolean field in a template file? I have a paragraph with a boolean field. 


content type
-paragraph entity reference 
left hand side paragraph 
checkbox
image
title


All the other fields have their own field-paragraph-field-checkbox.html.twig files and there's nothing to be checked, just adding a class around the image and title {{ item.content }} value.

However, I need to check if the checkbox field value is 1 or 0 in field-paragraph-field-checkbox.html.twig, and add a class if it's 1, or do nothing if it's 0. 

When I tried printing the value with {{ content.field_checkbox.value }} nothing prints. I also tried with {{ node.field_checkbox.value }}, but I don't get any value.

How do I check the value of a Boolean field in a template file?
I don't know how you debug but I think from question contest that trying  node.field_checkbox.0.value might work. Or if you are working with views and use views_get_view_results function, try content._entity.field_checkbox.value or content._entity.field_checkbox.0.value 0 used if field is untranslated

Update for comment: 

function TEMPLATE_theme_suggestions_page_alter(&amp;$suggestions, $variables) {

  // Check it's a node page.
  if (($node = \Drupal::routeMatch()-&gt;getParameter('node')) &amp;&amp; $node instanceof \Drupal\node\NodeInterface) {
    array_splice($suggestions, count($suggestions) - 1, 0, 'page__node__' . $node-&gt;getType());
  }
}


with this code in your TEMPLATE.theme file drupal 8 suggest page--node--CONTENT-TYPE-MACHINE-NAME.html.twig (Undersores to dushes). and thats it, You might have {{ kint(node) }} or {{ dump(node) }} in your twig.