- node (node) Is a network term , It represents a connection point in the network . A network is a collection of nodes .
- stay DOM in , A document is a collection of nodes , At this time, the nodes are branches and leaves on the document tree .
DOM Contains many different types of nodes , Let's introduce three of them ： Element nodes 、 Text nodes and attribute nodes .
1. Element nodes
explain ：DOM The atom of is an element node .
- The name of the element is the name of the tag .example： The name of the text paragraph element is “p”.
- Element can contain other elements .example： stay html In file ,\ The element is the root element of the node tree , Other elements , for example head、body etc. , Are contained in the root element .
2. Text node
explain ： Text nodes are always contained within element nodes , Its content is text . But it can't be said that all element nodes contain text nodes .
<p>This is an example.</p>
Above <p> In the elements ,“This is an example.” It's just a text node .
3. Attribute node
explain ： The attribute node is used to make a more specific description of the element .
</p><p title="an example title">This is an example.</p>
Above <p> In the elements , We can use title Property to describe this </p>
stay DOM in ,title="an example title" Is an attribute node .
Be careful ：
Attribute nodes are always placed in the start tag , That is, attribute nodes are always contained in element nodes .
But not all elements contain attributes , But all the attributes are contained in the element .