Author: yifei /
Created: July 27, 2017, 10:41 a.m. /
Modified: July 28, 2017, 3:26 p.m. /
HTML Document consists of different node, element is one type of node.
NodeList is a collection of node, HTMLCollection is a collection of element.
HTMLCollection 和 NodeList 都是动态的,会随着 DOM 的变化而变化