VBA 中的各种循环

利用循环和分支语句判断 B 列数字的符号，将结果填入 C列。

原始表格如如下：

 

 1、For 循环和 If 语句，代码如下：

Sub sign()
    Dim sign As String, i As Integer    '声明变量
    For i = 3 To 13 Step 1
        If Cells(i, "B") < 0 Then
            sign = "负数"
        ElseIf Cells(i, "B") > 0 Then
            sign = "正数"
        Else
            sign = "零"
        End If
        Cells(i, "C") = sign    '向 C 列对应单元格中写入数据
    Next i
End Sub

运行代码，结果如下：

 

2、For 循环和 Select Case 语句，代码如下：

Sub sign()
    Dim sign As String, i As Integer   '声明变量
    For i = 3 To 13 Step 1
        Select Case Cells(i, "B")
          Case Is < 0
            sign = "负数"
          Case Is > 0
            sign = "正数"
          Case Else
            sign = "零"
        End Select
        Cells(i, "C") = sign　　　　'向 C 列对应单元格中写入数据
    Next i 
End Sub    

 

 3、Do  While 循环和 Select Case 语句， 代码如下：

Sub sign()
    Dim sign As String, i As Integer　　　　　　'声明变量
    i = 3　　　　'初始化循环变量
    Do While Cells(i, "B") <> ""
        Select Case Cells(i, "B")
          Case Is < 0
            sign = "负数"
          Case Is > 0
            sign = "正数"
          Case Else
            sign = "零"
        End Select
        Cells(i, "C") = sign　　　　　　'向 C 列对应单元格中写入数据
        i = i + 1　　　　　　'更新哨兵变量
   Loop
End Sub

 

4、Do Until 循环和 Select Case 语句， 代码如下：

Sub sign()
    Dim sign As String, i As Integer　　　　　　'声明变量
    i = 3　　　　　　'初始化循环变量
    Do Until Cells(i, "B") = ""
        Select Case Cells(i, "B")
          Case Is < 0
            sign = "负数"
          Case Is > 0
            sign = "正数"
          Case Else
            sign = "零"
        End Select
        Cells(i, "C") = sign
        i = i + 1　　　　　　'更新循环变量
   Loop
End Sub