Editing NaN (section)

=== Signaling NaN ===
Signaling NaNs, or sNaNs, are special forms of a NaN that, when consumed by most operations, should raise the invalid operation exception and then, if appropriate, be "quieted" into a qNaN that may then propagate. They were introduced in [[IEEE 754]]. There have been several ideas for how these might be used:

* Filling uninitialized memory with signaling NaNs would produce the invalid operation exception if the data is used before it is initialized
* Using an sNaN as a placeholder for a more complicated [[object (computer science)|object]], such as:
** A representation of a number that has [[arithmetic underflow|underflowed]]
** A representation of a number that has [[arithmetic overflow|overflowed]]
** Number in a higher precision format
** A [[complex number]]
When encountered, a trap handler could decode the sNaN and return an index to the computed result. In practice, this approach is faced with many complications. The treatment of the [[sign bit]] of NaNs for some simple operations (such as [[absolute value]]) is different from that for arithmetic operations. Traps are not required by the standard.{{cn|date=September 2024}}