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(-1.0) |
+---------------+
|             1 |
+---------------+

select signbit(0.0);

+--------------+
| signbit(0.0) |
+--------------+
|            0 |
+--------------+

select signbit(1.0);

+--------------+
| signbit(1.0) |
+--------------+
|            0 |
+--------------+

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 |
+---------------------------------+---------------------------------+