http://stackoverflow.com/a/27335600/1678614

by Nelu Malancea

HTML

<ul>
  <li data-company="Microsoft">Steve</li>
  <li data-company="Google">Jobs</li>
  <li data-company ="Facebook">Michael</li>
  <li data-company ="Google">Richard</li>
  <li data-company ="Facebook">Tim</li>
</ul>

JavaScript

$("[data-company*='Microsoft'], [data-company*='Google']").css('font-weight','bold');