If...Then...Else Statement

Defines one or more statement blocks that you only want to execute if a given condition or expression is True.

  If condition Then 
      statements
  [{ElseIf|Else If} expression Then
      statements]
  [Else 
      statements]
  {EndIf|End If}

Instead of Else If you can write ElseIf, instead of End If you can write EndIf.

If statements can be shortened to one line when using single statement blocks.

  If condition Then statement [Else statement]

The If...Then statement executes program blocks depending on given conditions. When Collabora Office Basic encounters an If statement, the condition is tested. If the condition is True, all subsequent statements up to the next Else or ElseIf statement are executed. If the condition is False, and an ElseIf statement follows, Collabora Office Basic tests the next expression and executes the following statements if the condition is True. If False, the program continues either with the next ElseIf or Else statement. Statements following Else are executed only if none of the previously tested conditions were True. After all conditions are evaluated, and the corresponding statements executed, the program continues with the statement following EndIf.

「If...Then」语句可以多层嵌套。

「Else」和「ElseIf」语句是可选语句。

可以使用「GoTo」和「GoSub」跳出「If...Then」块，但是不能跳入「If...Then」结构。

以下示例可用于输入产品的有效期并确定产品是否已过期。

Sub ExampleIfThenDate
    Dim sDate As String
    Dim sToday As String
    sDate = InputBox("Enter the expiration date (MM.DD.YYYY)")
    sDate = Right$(sDate, 4) + Mid$(sDate, 4, 2) + Left$(sDate, 2)
    sToday = Date$
    sToday = Right$(sToday, 4)+ Mid$(sToday, 4, 2) + Left$(sToday, 2)
    If sDate < sToday Then
        MsgBox "The expiration date has passed"
    ElseIf sDate > sToday Then
        MsgBox "The expiration date has not yet passed"
    Else
        MsgBox "The expiration date is today"
    End If
End Sub