ValueIsNull Property (TDBDate)

Reference> TDBDate Control> TDBDate Control Properties> ValueIsNull Property (TDBDate)

ValueIsNull is a read only property, used to determine if the Value property holds a valid date or has a selection been made in the single selection mode. To determine if a selection was made when in the multiple selection mode, use the Count property in the Selections property.

Syntax

object.ValueIsNull

Read-only at run time. Not available at design time.

Values

True - Date in Value property is NULL

False - Date in Value property is not NULL

Remarks

ValueIsNull returns True if the Value property is set to Null, otherwise, ValueIsNull returns False. The Null value indicates that the Variant contains no valid data. Null is not the same as Empty, which indicates that a variable has not yet been initialized. It is also not the same as a zero-length string ("), which is sometimes referred to as a null string.

Use the ValueIsNull property to determine whether the Value property contains a Null value. Expressions that you might expect to evaluate to True under some circumstances, such as If Val = Null and If Val <> Null, are always False. This is because any expression containing a Null is itself Null and, therefore, False.

If either the DateSerial or the TimeSerial properties is set to Null, the Value property will also be set to Null.