Defining Variables and Constants
With the terminology and object-oriented programming concepts out of the way, we are ready to discuss the general syntax and structure of the LotusScript language starting with variables. There are essentially two steps required to utilize a variabledeclare and set. The DIM statement is used to declare variables in LotusScript. The syntax for declaring a variable is
DIM variablename AS declarationType
After the variable has been declared, you can the set the variable to a literal string, built-in data value, or object. For example, the following shows several variables being declared.
'--- Declare Regular Variables Dim TotalHolidays As Integer Dim ThisMonth As String Dim AuthorName As String '--- Declare Object Reference Variables Dim theDate As New NotesDateTime '--- Set the variables TotalHolidays = 5 ThisMonth = "January" theDate.LSLocalTime = Now
The following represents some of the built-in values that can be assigned to variables.
|
Constant |
Description |
|---|---|
|
NULL |
A special value that indicates "missing" or "unknown" data. It's important to understand that a NULL value does equate to an actual value. |
|
EMPTY |
Indicates that the variable does not contain a value. |
|
PI |
Sets the variable to the value of pi (which is the ratio between a circle's circumference and its diameter). |
|
trUE |
Sets the value of the variable to 1. |
|
FALSE |
Sets the value of the variable to 0. |
|
NOW |
The current date and time. |
|
TODAY |
The current date. |
Alternatively, you can declare regular variables by using the associated symbol. Using this method, the variable is automatically declared and set to the specified variable type. However, best practices suggest that you should always declare the variable.
CurrentDirectory$ = "C:" TotalHolidays% = 5
Constants hold a static value and are typically defined in LotusScript libraries. Constants can be defined throughout the application including in forms and subroutines. The syntax for declaring a constant is as follows.
[ Public | Private ] Const ConstName = expression
Public Indicates that the constant can be used outside the current module. This is an optional parameter.
Private Indicates that the constant is only visible within the current module. This is the default setting and is an optional parameter.
ConstName The name of the constant to be referenced throughout the LotusScript code. This value must be uniqueit cannot be the same name as another variable or constant.
expression The value to be assigned to the constant.
For example, the following illustrates several constants. As a best practice, consider using all caps or a unique prefix identifier such as "const" to denote a constant variable.
'--- Declare Constants Const MonthsInYear = 12 Const DaysInWeek = 7 Public Const PiValue = PI