嵌套 if 语句（nested if statements）

另一个If或ElseIf语句中的If或ElseIf语句。 内部If语句基于最外面的If语句执行。 这使VBScript可以轻松处理复杂的条件。

语法 (Syntax)

以下是VBScript中Nested If语句的语法。

If(boolean_expression) Then
   Statement 1
   .....
   .....
   Statement n
   If(boolean_expression) Then
      Statement 1
      .....
      .....
      Statement n
   ElseIf (boolean_expression) Then
      Statement 1
      .....
      ....
      Statement n
   Else
      Statement 1
      .....
      ....
      Statement n
   End If
Else
   Statement 1
	.....
	....
   Statement n
End If

例子 (Example)

出于演示目的，让我们在函数的帮助下找到正数的类型。

Private Sub nested_if_demo_Click()
   Dim a As Integer
   a = 23
   If a > 0 Then
      MsgBox "The Number is a POSITIVE Number"
      If a = 1 Then
         MsgBox "The Number is Neither Prime NOR Composite"
      ElseIf a = 2 Then
         MsgBox "The Number is the Only Even Prime Number"
      ElseIf a = 3 Then
         MsgBox "The Number is the Least Odd Prime Number"
      Else
         MsgBox "The Number is NOT 0,1,2 or 3"
      End If
   ElseIf a < 0 Then
      MsgBox "The Number is a NEGATIVE Number"
   Else
      MsgBox "The Number is ZERO"
   End If
End Sub

执行上述代码时，会产生以下结果。

The Number is a POSITIVE Number
The Number is NOT 0,1,2 or 3