Question

I am trying to understand how these jquery code work

function findVideoForElement(el) {
      var parentControls=$(el).parents('.video_controls[rel]');
      if (parentControls.length==0) {
            return $('video[id=]');
      } else {
            return $('#'+parentControls.attr('rel'));
      }
}

When parents() is called ,it returns the elements matching the expression '.video_controls[rel]' .What exactly does this expression mean.Is it class="video_controls" ? I could not figure out what the [rel] part means.

Also,does $('video[id=]') mean element with id=”video” ?

What would $('#'+parentControls.attr('rel')) return?

Answer 1

1. '.video_controls[rel]' means “has the class video_controls and has a rel attribute defined”
2. $('video[id=]') means “any <video> tag with an id attribute set to the empty string.
3. $('#' + parentControls.attr('rel')) would return the element with an id equal to the rel attribute on the parentControls element.

For more information on jQuery selectors, you can consult their documentation.