PHP self-learning path ----- basic introduction to XML programming (Xpath technology, simpleXml Technology)

The core idea of XPath design can be quickly introduced by xpath to locate the desired node. The main purpose is to describe the location of a node relative to another node. All qualified nodes can be obtained and become [location paths]. Xapth is mainly used to query information in XML documents. You can use path expressions to parse XML files and read the data in XML files. The following is a case study. The XML file is as follows (simplexml. xml): [php] <? Xml version = "1.0" encoding = "UTF-8"?> <Books> <book house = "qinghuachubanshe"> <code> sb001 </code> <price> 200 </price> <author> xiaoming </author> <title> tianlongbabu </title> </book> <book house = "beidachubanshe"> <code> sb002 </code> <price> 400 </price> <author> daming </author> <title> xiaoaojianghu </title> </book> </books> PHP code is as follows: [php] <? Php // 1 create a DOMDocument object $ dom = new DOMDocument ("1.0", "UTF-8"); // 2 load the Xml file $ dom-> load ("simplexml. xml "); // 3 convert to the DomXPath object $ xpath = new DOMXPath ($ dom ); // 4 search for work $ node_list = $ xpath-> query ("/books/book/title"); echo "Total ". $ node_list-> length. "<br/>"; for ($ I = 0; $ I <$ node_list-> length; $ I ++) {$ node = $ node_list-> item ($ I); // var_dump ($ node_list);/* foreach ($ node as $ key => $ val) {echo