Sandra is working with an XML file containing product orders with the structure shown in the accompanying figure. She was just introduced to step patterns, and would like to incorporate them into the style sheet she is developing to display the orders data. She comes to you for help in developing expressions incorporating step patterns.
-Sandra would like to write an expression to show only those orders that have a preceding sibling containing the same orderDate . Which of the following do you tell her is the correct expression?
A) orderDate=preceding::order/orderDate
B) not(orderDate=preceding::order/orderDate)
C) orderDate=ancestor::order/orderDate
D) not(orderDate=ancestor::order/orderDate)

Question

Sandra is working with an XML file containing product orders with the structure shown in the accompanying figure. She was just introduced to step patterns, and would like to incorporate them into the style sheet she is developing to display the orders data. She comes to you for help in developing expressions incorporating step patterns.
-Sandra would like to write an expression to show only those orders that have a preceding sibling containing the same orderDate . Which of the following do you tell her is the correct expression?
A) orderDate=preceding::order/orderDate 
B) not(orderDate=preceding::order/orderDate) 
C) orderDate=ancestor::order/orderDate 
D) not(orderDate=ancestor::order/orderDate)

Quizplus · Accepted Answer

The correct expression for showing only those orders that have a preceding sibling containing the same orderDate is "orderDate=preceding::order/orderDate". This means that the value of the current orderDate is equal to a previous orderDate value in the same order element. The other expressions are incorrect because they either check for the orderDate value in the ancestor element (C and D) or negate the correct expression (B).

Sandra Is Working with an XML File Containing Product Orders