Returns the value of the context node, converted to an xs:double. This is a parameterless variant of the number function where the context node is determined by the connections in your mapping. To specify a node explicitly, use the number function that takes an input node as parameter.
The only types that can be converted to numbers are Booleans, numeric strings, and other numeric types. Non-numeric input values (such as a non-numeric string) result in NaN (Not a Number).
XQuery, XSLT 2.0.