Xpath correction check please

Question

Given XML:

  <?xml version="1.0" encoding="UTF-8"?> 
     <sensor-system>
        <velocity>120.00</velocity> <!-- km/h --> 
        <temperature location="inside">24.6</temperature> 
         <temperature location="outside">-12.5</temperature>

     <seats>

     <seat location="front">
          <id>1</id> 
          <temperature>32.5</temperature> 
          <heating-is-on/>

      </seat> 
    <seat location="back">

      <id>2</id>
      <temperature>23.5</temperature>
   </seat>

</seats>
  </sensor-system>

Required XML path:

Give an absolute XPATH that identifies all front seats with a temperature greater than or equal to 20.0 and less than or equal to 30.0 degrees celsius.

My solution please check:

Is this correct :

/sensor-system/seats[temperature>=20 | temperature <=30]/seat[@location="front"]

Thank you.

Answer 1

You xpath is not quite correct because it is expecting the temperature element to be a child of the seats element, when you should be checking the seat element.

EDIT: Another thing to point out that in your original xpath, you are using the '|' operator, which is the union operator, and which takes two node-sets as arguments. So it won't work in your example, as your arguments are actually 'conditions'.

Try this instead

/sensor-system/seats/seat[temperature >= 20][temperature <= 30][@location = "front"]

Note, if you were using this in XSLT, you might have to escape the < here

/sensor-system/seats/seat[temperature >= 20][temperature <= 30][@location = "front"]

Although you may prefer to do this

/sensor-system/seats/seat[temperature >= 20][not(temperature > 30)][@location = "front"]

Answer 2

Try doing this :

/sensor-system/seats/seat[@location="front"]/temperature >=20 and /sensor-system/seats/seat[@location="front"]/temperature <= 30

This will be true for [@location="back"] and false for [@location="front"]