VBA中简单的递归函数，Excel不返回预期结果 [英] Simple recursive function in VBA with Excel not returning expected result

问题描述

我有一个简单的递归函数来写入VBA，它执行以下操作：它必须计算次数，我们必须使用参数x的日志来查找log（x）< 1

示例：

• logcount（5）：log（5）= 0,6 ...所以函数应该返回1


• logcount（89）：log（89）= 1,9 ...和log（log（89））= 0， 28 ...所以函数应该返回2


• logcount（0,4）应该返回1
  etc ...

所以我写了它，它不按预期工作！它总是为结果添加+1！它看起来像最后一个Else块总是被解释。任何帮助将非常感谢

 函数logcount（x As Double）As Integer 
如果x <= 0则
 MsgBox您必须输入正值
退出函数
 ElseIf Log（x）< 1然后
 logcount = 1 
 Else 
 logcount = 1 + logcount（Log（x））
 End If 
 End Function 
  

解决方案

VBA中的日志是自然对数。

显然你的意思是一个10位的对数：

  Log10 = Log（X） / Log（10＃）
  

I have a simple recursive function to write in VBA that does the following : It must count the number of times we must take the log of a parameter 'x' to find log(x) < 1

Examples :

• logcount(5) : log(5) = 0,6... so the function should return 1
• logcount(89) : log(89) = 1,9... and log(log(89)) = 0,28... so the function should return 2
• logcount(0,4) should return 1 etc...

So I wrote it and it doesn't work as expected ! It always adds +1 to the result ! It looks like the last 'Else' block is always interpreted. Any help will be really appreciated

Function logcount(x As Double) As Integer
  If x <= 0 Then
    MsgBox "You must enter a positive value"
    Exit Function
  ElseIf Log(x) < 1 Then
    logcount = 1
  Else
    logcount = 1 + logcount(Log(x))
  End If
End Function

解决方案

Log in VBA is the natural logarithm.

Apparently you meant a base-10 logarithm:

Log10 = Log(X) / Log(10#)

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