※ 引述《fumizuki (小狮子)》之铭言： : Private Sub Command1_Click(Index As Integer) : Text1.Text = Text1.Text & Index : End Sub : Private Sub Command2_Click(Index As Integer) : Text1.Text = Text1.Text & Command2(Index).Caption : End Sub : Private Sub Command3_Click() : Label1.Caption = Eval(Text1.Text) : End Sub : Function Eval(s As String) : Dim p As Integer, op1 As String, op2 As String, o As String : Static c As Integer: c = c + 1 : If c = 1 Then s = Replace(s, " ", "") : p = InStr(s, "+") : If p > 0 Then GoSub SplitProc: Eval = Eval(op1) + Eval(op2): GoTo EndProc : If s Like "-*" Then p = 2 Else p = 1 : p = InStr(p, s, "-") : If p > 0 Then : op1 = Mid(s, p - 1, 1) : If op1 = "+" Then : p = p - 1: GoSub SplitProc: Eval = Eval(op1) + Eval(op2): GoTo EndProc : ElseIf op1 = "-" Then : p = p - 1: GoSub SplitProc: Eval = Eval(op1) - Eval(op2): GoTo EndProc : ElseIf op1 = "*" Then : p = p - 1: GoSub SplitProc: Eval = Eval(op1) * Eval(op2): GoTo EndProc : ElseIf op1 = "/" Then : p = p - 1: GoSub SplitProc: Eval = Eval(op1) / Eval(op2): GoTo EndProc 我在这边加入一个: ElseIf op1 = "^" Then p = p - 1: GoSub SplitProc : Else : GoSub SplitProc: Eval = Eval(op1) + Eval("-" & op2): GoTo EndProc : End If : End If : p = InStr(s, "*") : If p > 0 Then GoSub SplitProc: Eval = Eval(op1) * Eval(op2): GoTo EndProc : p = InStr(s, "/") : If p > 0 Then GoSub SplitProc: Eval = Eval(op1) / Eval(op2): GoTo EndProc 这边加入一个: p = InStr(s, "^") If p > 0 Then GoSub SplitProc: F = F(op1) ^ F(op2): GoTo EndProc : Eval = Val(s) : EndProc: : c = c - 1: Exit Function : SplitProc: : op1 = Left(s, p - 1): op2 = Mid(s, p + 1): Return : End Function 没想到竟然也可以算次方,可是我想不出原理是什麽 如果说程式执行到^的时候,字串已经里面不会再有加减乘除号了, 这样 p = InStr(s, "^") If p > 0 Then GoSub SplitProc: F = F(op1) ^ F(op2): GoTo EndProc 这边就可以理解 但是这边 ElseIf op1 = "^" Then p = p - 1: GoSub SplitProc 如果-前面有^,後面有*, 例如:Eval(5^-3*2)的时候 照理说,我没有设定Eval=Eval(op1) ^ Eval(op2): (因为设了会出错) Eval(5^-3*2)应该无法分割,但是答案却出乎我预料的正确@@!! -- 少年读书，如隙中窥月； 中年读书，如庭中望月； 老年读书，如台上玩月。 --

※ 发信站: 批踢踢实业坊(ptt.cc) ◆ From: 220.141.159.236