IsNull Method for LCField

This method returns true or false depending on whether the specified field data is NULL. A field may potentially contain multiple values, some of which are null and others not.

Defined in

LCField

Syntax

flag = thisfield.IsNull (index)

Parameters

Parameter

Description

index

Long. Index identifying the field.

Return Value

Value

Description

flag

Boolean value, either TRUE or FALSE.

Example

Option Public
Uselsx "*lsxlc"  
Sub Initialize
  Dim field As New LCField (LCTYPE_INT, 4) ' four values in one field.
  Dim i%
  Call field.SetInt(1, 2020)
  Call field.SetInt(4, 12)
  For i = 1 To 4
    If field.IsNull(i) Then
      Print "value " & i & " is null"
    Else
      Print "value " & i & " = " & field.GetInt(i)
    End If
  Next
End Sub

Example Output

value 1 = 2020
value 2 is null
value 3 is null
value 4 = 12