Question

编辑：大部分修订后的代码发布在下面。

编辑：我希望让用户输入多项式，例如：A（n）* X ^ n + A（n-1）* X ^（n-1）+ A（n-2）* X ^（ n-2）+ ... + A（0）

我正在使用Excel宏来演示中间值定理。用户输入A2中的Degree，B2中的Coefficient。

目前，MsgBox可以以Coefficient * x ^ Degree的形式返回一阶多项式。我希望MsgBox能够返回更复杂的多项式，以便用户可以确认输入了正确的多项式。

这是代码：

Sub Function1()
MsgBox "Enter polynomial by terms."

counter = 1
counter = counter + 1
Degree = Cells(counter, 1).Value 'A2
Coefficient = Cells(counter, 2).Value 'B2
'   If cell value is null stop
If IsNull(Degree) = True Then
    MsgBox "IsNull(Degree)=True"
End If
If IsNull(Coefficient) Then
    MsgBox "IsNull(Coefficient)=True"
End If
If IsNumeric(Len(Trim(Degree))) = True And IsNumeric(Len(Trim(Coefficient))) Then
    MsgBox "Degree is numeric"
    If Degree Mod 1 = 0 Then
        MsgBox "Degree is integer"
    End If
End If
MsgBox Coefficient & "x^" & Degree
'   How repeat this process to show in MsgBox entire polynomial?
End Sub

编辑：修订后的代码：

Option Explicit
Sub Function1()
Dim Polynomial As String
Dim Sign
Dim counter As Integer
Dim Degree
Dim Coefficient

While Cells(counter + 1, 1).Value <> "" And Cells(counter + 1, 2).Value <> "" '+1 because top row occupied by column A, column B titles. If cell is empty stop.
MsgBox "Enter polynomial by terms."
Degree = Cells(counter + 1, 1).Value 'A2
Coefficient = Cells(counter + 1, 2).Value 'B2
If (Coefficient < 0) Then Sign = " - " ' if coefficient negative
    Else: If Coefficient > 0 Then Sign = " + " ' if coefficient positive
End If
Polynomial = Polynomial & " " & Coefficient & "x^" & Degree 'concatenation string, list polynomial.
counter = 1
counter = counter + 1
Wend
MsgBox poly
End Sub

Answer 1

您需要围绕已编写的内容构建一个循环，并在Coefficient & "x^" & Degree变量内汇总String。它看起来像这样：

Dim poly as String
Dim sign as String

' Iterate over data cells:
while Cells(counter,1).Value <> ""
    ' What you're already doing...
    ' ...plus:
    IIf(Coefficient < 0, sign = " - ", sign = " + ")

    ' String concatenation:
    poly = poly & " " & Coefficient & "x^" & Degree
    counter=counter+1
Wend
' Finally:
Msgbox poly

编辑：此外，如果要检查空值，请使用If Cells(counter,1).value = "" Then ...。 IsNull用于检查对象是否为空;简单数据类型初始化为"" String和0数字，因此永远不会触发isNull。

如何三元解析单元格值以形成多项式表达式？

1 个答案: