XML allows hyphens (-
) in names. Consequently, the subtraction operator (-
) typically needs to be preceded by white space. For example, foo-bar
evaluates to a node set that contains the child elements named foo-bar
. However, foo
-
bar
evaluates to the difference between the result of converting the string value of the first foo
child element to a number and the result of converting the string value of the first bar
child to a number.