XPath - 布尔运算符



XPath 定义了以下布尔运算符,用于 XPath 表达式。

序号。 运算符 & 说明
1

and

两个条件都要满足

2

or

满足任一条件即可

3

not()

用于检查不满足条件的函数。

示例

本示例通过逐个迭代每个学生来创建一个表,其中包含 <student> 元素及其属性学号和子元素 <firstname>、<lastname><nickname> 和 <marks>。它检查学号为 393 或 493,然后打印学生的详细信息。

students.xml

<?xml version = "1.0"?>
<?xml-stylesheet type = "text/xsl" href = "students.xsl"?>
<class>
   <student rollno = "393">
      <firstname>Dinkar</firstname>
      <lastname>Kad</lastname>
      <nickname>Dinkar</nickname>
      <marks>85</marks>
   </student>
   <student rollno = "493">
      <firstname>Vaneet</firstname>
      <lastname>Gupta</lastname>
      <nickname>Vinni</nickname>
      <marks>95</marks>
   </student>
   <student rollno = "593">
      <firstname>Jasvir</firstname>
      <lastname>Singh</lastname>
      <nickname>Jazz</nickname>
      <marks>90</marks>
   </student>
</class>

students.xsl

<?xml version = "1.0" encoding = "UTF-8"?>
<xsl:stylesheet version = "1.0"
   xmlns:xsl = "http://www.w3.org/1999/XSL/Transform">  

   <xsl:template match = "/">
      <html>
         <body>
            <h2>Students</h2>
				
            <table border = "1">
               <tr bgcolor = "#9acd32">
                  <th>Roll No</th>
                  <th>First Name</th>
                  <th>Last Name</th>
                  <th>Nick Name</th>
                  <th>Marks</th>
               </tr>
					
               <xsl:for-each select = "class/student[(@rollno = 393) or ((@rollno  =  493))]">
					
                  <tr>
                     <td><xsl:value-of select = "@rollno"/></td>
                     <td><xsl:value-of select = "firstname"/></td>
                     <td><xsl:value-of select = "lastname"/></td>
                     <td><xsl:value-of select = "nickname"/></td>
                     <td><xsl:value-of select = "marks"/></td>
                  </tr>
               </xsl:for-each>
            </table>
         </body>
      </html>
   </xsl:template>
</xsl:stylesheet>

验证输出

Formatted Boolean Operator Output
xpath_operators.htm
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