XSLT and XPATH: A Guide to XML Transformations

5.5 . Number Core Function Group

The number functions all return a number as their function return type. It contains five functions, one of which, number(), serves as the fundamental conversion of any object to a number.

The five functions in the number core function group are covered below, beginning with the number() conversion function, which takes an optional object argument to be converted to a number. This function is similar to string() and boolean() in that it works ubiquitously under the hood while not frequently being explicitly called itself. Following this is the sum() function, which serves to convert a required node-set object's string value to a number. The remaining three functions include a top-end test of a given numerical sequence, ...