Name

xs:double

Synopsis

Defined in: XML Schema part 2

This datatype maps directly to the XPath concept of number, and thus can be useful in situations where data flows back and forth between XPath and the XML instance data.

Caveats

Unlike the decimal datatypes, xs:double is based on an internal binary representation, so many operations (particularly comparisons) are only approximations. The lexical space of this datatype allows scientific notation, so you need to be careful not to assume that any particular representation will always be used. Also, special values of NaN (not a number), INF (infinity), -INF (negative infinity), as well as negative zero, are possible. NaN in particular behaves strangely in comparisons, being equal to itself and greater than all other numbers, even INF!

Examples

  • 3.14159

  • 3.14159E0

  • NaN

  • 0

  • -0

  • INF

  • -INF

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