XPath Boolean Operators
You can also use the
or operators within your XPath expressions. These are referred to as "boolean operators", as they only test for "true" or "false".
With boolean operators, numbers return false if they are zero, otherwise they return true. Empty strings (i.e.
"") return false, otherwise they return true.
Boolean Operator Usage Example
The Source XML File
Using the same XML file, containing 13 food items and their associated nutritional value:
This time, we will only display items that are either vegetables or fruit (remember, we have specified this using the
type attribute). Like this:
We could modify the code to test the value of the
type attribute. We could achieve this using the XPath
or operator to test that the value contains
fruit, as follows: