How to add automatic class in image for wordpress post

Question

I want to make a responsive theme with Bootstrap 3. However, I need to automatically add the CSS class .img-responsive to every post image because I need the i

Answer 1

I had the same question, and adding this function to functions.php worked for me.

function add_image_responsive_class($content) {
   global $post;
   $pattern ="//i";
   $replacement = '';
   $content = preg_replace($pattern, $replacement, $content);
   return $content;
}
add_filter('the_content', 'add_image_responsive_class');