根據特定的子節點選擇節點

示例 XML

 <Students>
    <Student>
        <Name>
            <First>Ashley</First>
            <Last>Smith</Last>
        </Name>
        <Grades>
            <Exam1>A</Exam1>
            <Exam2>B</Exam2>
            <Final>A</Final>
        </Grades>
    </Student>
    <Student>
        <Name>
            <First>Bill</First>
            <Last>Edwards</Last>
        </Name>
        <Grades>
            <Exam1>A</Exam1>
        </Grades>
    </Student>    
</Students>

XPath 的

選擇所有記錄了 Exam2 分數的學生

//Student[./Grades/Exam2]

要麼

//Student[.//Exam2]

輸出

<Student>
    <Name>
        <First>Ashley</First>
        <Last>Smith</Last>
    </Name>
    <Grades>
        <Exam1>A</Exam1>
        <Exam2>B</Exam2>
        <Final>A</Final>
    </Grades>
</Student>