SIGNBIT

Description

Determine whether the sign bit of the given floating-point number is set.

Syntax

SIGNBIT(<a>)

Parameters

Parameter	Description
<a>	Floating-point number to check the sign bit for

Return Value

Returns true if the sign bit of <a> is set (i.e., <a> is negative), otherwise returns false. Specifically, it can also distinguish between positive and negative zeros in floating-point numbers.

Examples

select signbit(-1.0);

+-----------------------------+
| signbit(cast(-1 as DOUBLE)) |
+-----------------------------+
| true                        |
+-----------------------------+

select signbit(0.0);

+----------------------------+
| signbit(cast(0 as DOUBLE)) |
+----------------------------+
| false                      |
+----------------------------+

select signbit(1.0);

+----------------------------+
| signbit(cast(1 as DOUBLE)) |
+----------------------------+
| false                      |
+----------------------------+

select signbit(cast('+0.0' as double)) , signbit(cast('-0.0' as double));

+---------------------------------+---------------------------------+
| signbit(cast('+0.0' as double)) | signbit(cast('-0.0' as double)) |
+---------------------------------+---------------------------------+
|                               0 |                               1 |
+---------------------------------+---------------------------------+