InsertBefore relative to AppendChild

Node.insertbefore (newnode,existingnode)

Node.appendchild (node)

1. InsertBefore relative to AppendChild, it is more flexible to insert a new node into any position in the destination node array. 2, using AppendChild and InsertBefore to insert a new node, the premise is that its sibling node must have a common parent node 3, AppendChild () method to add the last child node to the node. You can also use the AppendChild () method to move elements from one element to another, a presentation: http://www.w3school.com.cn/tiy/t.asp?f=jsref_node_appendchild2

InsertBefore relative to AppendChild