Result = IsBoolean ( vExpression ) AS Boolean
Result = Boolean? ( vExpression ) AS Boolean

Returns TRUE if the vExpression is Boolean.

Examples

PRINT IsBoolean(FALSE), IsBoolean((1 > 0) AND (2 > 1)), IsBoolean(IsBoolean("no matter what"))
True    True    True

PRINT IsBoolean(-1), IsBoolean(NULL)
False   False