Thumbnail remove width & height function

Question

I wish that when the browser was resized to below 980px, my images were width 100%. The container of the images already have 100%, the problem is that I'm using wordpress size code for thumbnails:

add_theme_support ('post-thumbnails');
add_image_size ('portfolio1', 600, 344, true);

So I thought to use this code to remove the image sizes:

jQuery (document). ready (function ($) {
     $ ('img'). RemoveProp ('width'). RemoveProp ('height');
});

The problem is that I do not know how it would look for smaller sizes that 980px browser. I do not know if this is the best way. I Would like some help Thank you

Answer 1

This snippes should remove the height and width attributes of the images: https://gist.github.com/stuntbox/4557917

Maby you would extend the code to only strip out the attributes on images larger than 980px?.