DOM introduction

One 、 What is? DOM

​ Document object model （Document Object Model, abbreviation DOM）, yes W3C Handling of organizational recommendations Extensible markup language （html perhaps xhtml） Standards for Programming interface (API) .

​ W3C A series of DOM Interface , Through these DOM Interface can change the content of a web page 、 Structure and pattern .

Two 、DOM Trees

As shown in the figure

DOM Tree is also called document tree model , Map the document to a tree structure , It is processed by node objects , The result of processing can be added to the current page

1 file ： A page is a document stay DOM of use document To express
2 node Everything in the web page There is a node in the document tree （ label ,
attribute , Text , Annotations, etc. ）, Yes, it is node To express
3 Tag node ： All the tags in the web page It is often called an element node , Also referred to as element Use element To express

It should be noted that DOM Think of all the above as objects