I'm working in Java with XML and I'm wondering; what's the difference between an element and a node?
The Node object is the primary data type for the entire DOM.
A node can be an element node, an attribute node, a text node, or any other of the node types explained in the "Node types" chapter.
An XML element is everything from (including) the element's start tag to (including) the element's end tag.
Different W3C specifications define different sets of "Node" types.
Thus, the DOM spec defines the following types of nodes:
Document
-- Element
(maximum of one), ProcessingInstruction
, Comment
, DocumentType
DocumentFragment
-- Element
, ProcessingInstruction
, Comment
, Text
, CDATASection
, EntityReference
DocumentType
-- no children EntityReference
-- Element
, ProcessingInstruction
, Comment
, Text
, CDATASection
, EntityReference
Element
-- Element
, Text
, Comment
, ProcessingInstruction
, CDATASection
, EntityReference
Attr
-- Text
, EntityReference
ProcessingInstruction
-- no children Comment
-- no children Text
-- no children CDATASection
-- no children Entity
-- Element
, ProcessingInstruction
, Comment
, Text
, CDATASection
, EntityReference
Notation
-- no children The XML Infoset (used by XPath) has a smaller set of nodes:
XPath has the following Node types:
The answer to your question " What is the difference between an element and a node " is:
An element is a type of node. Many other types of nodes exist and serve different purposes.
A Node is a part of the DOM tree, an Element is a particular type of Node
eg <foo> This is Text </foo>
You have a foo Element, (which is also a Node, as Element inherits from Node) and a Text Node 'This is Text', that is a child of the foo Element/Node
节点可以是许多不同类型的东西:一些文本,一个注释,一个元素,一个实体等。元素是一种特殊的节点。
As described in the various XML specifications , an element
is that which consists of a start tag, and end tag, and the content in between, or alternately an empty element tag (which has no content or end tag). In other words, these are all elements:
<foo> stuff </foo>
<foo bar="baz"></foo>
<foo baz="qux" />
Though you hear "node" used with roughly the same meaning, it has no precise definition per XML specs. It's usually used to refer to nodes of things like DOMs, which may be closely related to XML or use XML for their representation.
An xml document is made of nested elements. An element begins at its opening tag and ends at its closing tag . You're probably seen <body>
and </body>
in html. Everything between the opening and closing tags is the element's content . If an element is defined by a self-closing tag (eg. <br/>
) then its content is empty.
Opening tags can also specify attributes , eg. <p class="rant">
. In this example the attribute name is 'class' and its value 'rant'.
The XML language has no such thing as a 'node' . Read the spec , the word doesn't occur.
Some people use the word 'node' informally to mean element, which is confusing because some parsers also give the word a technical meaning (identifying 'text nodes' and 'element nodes'). The exact meaning depends on the parser, so the word is ill-defined unless you state what parser you are using. If you mean element, say 'element' .
节点是元素和属性的基类(基本上也是所有其他XML表示)。
Element is the only kind of node that can have child nodes and attributes.
Document also has child nodes, BUT
no attributes, no text, exactly one child element.
A node is defined as:
the smallest unit of a valid, complete structure in a document.
or as:
An object in the tree view that serves as a container to hold related objects.
Now their are many different kinds of nodes as an elements node, an attribute node etc.
Now i know ,the element is one of node
All node types in here" http://www.w3schools.com/dom/dom_nodetype.asp "
Element is between the start tag and end in the end tag
So text node is a node , but not a element.
元素是一种节点,属性,文本等。
XML Element is a XML Node but with additional elements like attributes.
<a>Lorem Ipsum</a> //This is a node
<a id="sample">Lorem Ipsum</a> //This is an element
node & element are same. Every element is a node , but it's not that every node must be an element.
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