LOTUSSCRIPT LANGUAGE
Examples: IsElement function
' Use IsElement to determine whether

' the user correctly identifies a list tag.

' Declare a list to hold employee Ids.

Dim empList List As Double

Dim empName As String, Id As Double

Dim found As Boolean

' Create some list elements and assign them values.

empList#("Maria Jones") = 12345

empList#("Roman Minsky") = 23456

empList#("Joe Smith") = 34567

empList#("Sal Piccio") = 91234

' Ask the user to identify the list item to be removed.

empName$ = InputBox$("Which employee is leaving?")

' Check to see if empName$ corresponds to a list tag.

' If not, display a message and stop. Otherwise,

' validate the employee's Id.

' If everything checks out, remove the item from the list.

If IsElement(empList#(empName$)) = TRUE Then

  Id# = CDbl(InputBox$("What's " & empName$ & "'s Id?"))

  found = FALSE          ' Initialize found to 0 (FALSE)

  ForAll empId In empList#

     If empId = Id# Then

        found = TRUE     ' Set found to -1 (TRUE).

        If ListTag(empId) = empName$ Then

           Erase empList#(empName$)

           ' Verify the removal of the list element.

           If IsElement(empList#(empName$)) = FALSE Then

              MessageBox empName$ & _

                 " has been removed from the list."

           End If

        Else

           MessageBox "Employee name and Id do not match."

        End If

        ' No need to look farther for Id, so get out

        ' of the ForAll loop.

        Exit ForAll

     End If

  End ForAll

  If found = FALSE Then

     MessageBox "Not a valid employee Id."

  End If

Else

  MessageBox "We have no such employee."

End If

See Also