Select an element or list of elements

Select an element by given ID

<div id="hello" />;
document.getElementById('hello');

Select elements by class name

Returns the list of elements that have hello class within a given element:
ele.getElementsByClassName('hello');

Select elements by tag name

Returns the list of span inside a given element:
ele.getElementsByTagName('span');

Select elements by CSS selector

Returns the list of elements that match a given selector:
ele.querySelectorAll('div.hello');
Returns the first element that match a given selector:
ele.querySelector('div.hello');

See also