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小林编写了一个用于1至9之间整数加减乘除运算的小程序,具体功能如下:在文本框 Text1中输入一个算术表达式(该表达式仅包含1至9之间的整数和加减乘除运算符,其中最后一个运算符肯定是乘或除,且乘或除运算符的前和后一个运算符仅可能为加减或没有),单击“计算”按钮Command1,将运算结果显示在 Label2中。程序运行界面如图所示,实现上述功能的VB程序如下,请回答下列问题:

(1)将窗体标题更改为“简单算术运算”,应修改窗体的________________属性的属性值。
(2)请在划线处填入合适的代码。
(3)加框处的代码有错误,请改正。
Private Sub Commandl_ Click()
Dim s As String, c As String, i As Integer
Dim sum As Single, suml As Single, sum2 As Single, k As Integer, j As Integer
s= Text1. Text: sum2= 0:k=1
For i= I To Len(s)
c= ____________________

If c=“*” Or c=“/”Then

If c=“*” Then
sum= Val (Mid (s, i+ 1. 1)* Val (Mid (s, i- 1, 1))
Else
sum= Val (Mid (s, i- 1,1)/Val (Mid (s, i+ 1, 1))
End If
j= i-2
Do While ________
c= Mid(s, j, D)
If c=“+” Then suml- Val (Mid (s, j- l, 1))+sum
If c=“-” Then suml – Val (Mid (s, j-1, i))-sum
sum= sum1
j= j- 1

Loop

If  k= 1 Then

sum2= sum2 + sum

Else

c= Mid(s, k, 1)
If c=“+”Then sum2= sum2 + sum
If c=“-”Then sum2= sum2- sum

End If

k= _________________

End If
sum = 0
Next i
Label2. Caption=sum2
End Sub
上一题 下一题 0.99难度 None 更新时间:2020-03-28 10:19:21

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同类题3

【加试题】小王模拟超市收银机扫描商品条形码后计算总价的过程制作了一个VB程序。功能如下:在文本框Text1中输入商品条形码,按回车键后会将已经输入的条形码显示在列表框List1中,同时将商品明细显示在列表框List2中。点击按钮“计算商品总价”后,会将所有商品的总价显示在文本框Text2中。程序界面如图所示:

实现上述功能的部分VB程序如下,请在三个划线处填入合适代码。
'定义全局数组变量
Dim a(1 To 10) As Long
Dim b(1 To 10) As String
'自动加载条形码信息以及对应的商品信息
Private Sub Form_Load()
Dim i As Integer
a(1) = 503741
For i =" 2" To 10
a(i) =" a(i" - 1) + 1
Next i
b(1) = "可乐 5.00"
b(2) = "薯片 7.50"
b(3) = "牛奶 5.60"
b(4) = "橙汁 7.50"
b(5) = "面包 4.00"
b(6) = "蜂蜜 28.00"
b(7) = "蛋糕 12.00"
b(8) = "绿箭 3.50"
b(9) = "饼干 6.00"
b(10) = "雪碧 5.00"
End Sub
'输入条形码,查找条形码,并显示条形码及其对应的商品信息
Private Sub Text1_KeyPress(KeyAscii As Integer)
Dim txm As Long:
Dim i As Integer:
Dim j As Integer
txm = Val(Text1.Text)
If KeyAscii =" 13" Then
If txm >=" 503741" And txm <=" 503750" Then
List1.AddItem txm
Text1.Text = ""
i =" 1:" j = 10
Do While i <= j
    ①
If txm =" a(m)" Then
List2.AddItem b(m)
Exit Do
ElseIf txm > a(m) Then
i =" m" + 1
Else
   ②   
End If
Loop
Else
MsgBox "条形码输入错误,无此商品"
Text1.Text = ""
End If
End If
End Sub
'计算所购商品的总额
Private Sub Command1_Click()
Dim i As Integer, mx As String, jg As String, sum As Single
For i =" 0" To 9
If List2.List(i) <> "" Then
mx = List2.List(i)
sum =" sum" + Mid(mx, 4)
End If
Next i
Text2.Text = ③    
End Sub