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

When you display post in your loop, you could do :

the_post_thumbnail('thumbnail', array('class' => 'img-responsive'));

See https://codex.wordpress.org/Function_Reference/the_post_thumbnail for more details.