Finding HTML Element by Id
Return the element with id="id01":
Finding HTML Elements by Tag Name
Return all <p> elements:
Finding HTML Elements by Class Name
Return all elements with class="intro".
Finding elements by class name does not work in Internet Explorer 8 and earlier versions.
Finding HTML Elements by CSS Selectors
Return a list of all <p> elements with class="intro".
The querySelectorAll() method does not work in Internet Explorer 8 and earlier versions.