a=12
b=54
a=b
b=a
该程序段运行后,a,b的值分别为、,该程序结构属于结构(选填:顺序、选择、循环)。
Dim n As Integer,a(100)As Integer,max As Integer
Private Sub Form_Load() ‘读取原始数据
Dim conn As New ADODB.Connection.rs As New ADODB.Recordset
Dim i As Integer
conn.ConnectionString=”Provider=Microsoft.ACE.OLEDB.12.0;Data
Source=”&App.Path&。”\student.accdb”
conn.Open
Set rs.ActiveConnection=conn
rs.Open“SELECT*FROM DF”
i=0:max=0
Do While Not rs.EOF
i=i+1:n=i
a(i)= ‘①
If a(i)>max Then max=a(i)
rs.MoveNext
Loop
rs.Close:conn.Close
End Sub
Private Sub Command1_Click() ‘去重复值排序
Const t=max
Dim i As Integer,b(t)As Integer
For i=1 To n
B(a(i))=b(a(i))+1
Next i
For i=1 To t
If Then List1.AddItem Str(t-i+1) ‘②
Next i
End Sub
①处加框代码应改为;
②处加框代码应改为。
s = "Hello, Taizhou!"
n= Len(s): ans =""
For i=1 To n
c=Mid(s, i, 1))
If Abs(i-n)<n\2 Then
If c>="a" And c<="z" Then c=Char(Asc(c)-Asc("a")+Asc("A"))
End If
ans=ans+c
Next i
Labell.Caption=ans
执行上述程序段后,标签Labell中输出的内容为( )
实现上述功能的VB代码如下,但加框处有错,请改正。
Private Sub Command1_Click()
Dim n As Integer, m As Integer
Dim a(1 To 50)As Integer
n= Val(Text1. Text)
m= Val(Text2. Text)
For i= 1 To n
Next i
s=0;j=0
Do While s <n
t=0
Do While t <m
①
t=t+ a(j)
Loop
a(j)=0
s=s+1
List1. Additem"第"+Str(s)+"次:"+Str(j)
Loop
End sub
For i=1 To 9
For j=10 To i+2 Step-1
If a(j)<a(j-2) Then
t=a(j): a(j)=a(j-2): a(j-2)=t
End If
Next j
Next i
数组元素a(1)到a(10)的值依次为“3,17,2,14,15,6,7,18,9,4”,执行该程序段后,数组元素a(8)中的值为( )
n=1
for i in range(0,5):
n=n*i
print(n)
s=Text1.Text
ans=0
Text2.Text=Str(ans)
若Text1中输入的内容为“10”则Text2中输出的内容为“2”,加框处代码,不正确的是( )。
t=Val(Mid(s, i, 1))
ans=ans+t*2^(Len(s)-i)
Next i
B . For i=1 To Len(s)t=Val(Mid(s, i, 1))
ans=ans*2+t
Next i
C . For i=Len(s) To 1 step-1t= Val(Mid(s, i, 1))
ans=ans+t*2^(i-1)
Next i
D . For i=1 To Len(s)t=Val(Mid(s, Len(s)-i+1, 1))
ans=ans+t*2^(i-1)
Next i
n =1
For i=2 To 12
If ⑴ Then
n=n+1
⑵
End If
Next i
S=””
For i=1 To n
s=s+Str(a(i))
Next i
Text1.Text = s
上述程序中划线处可选语句为:①a(i)<>a(n) ②a(i)=a(n) ③a(n)=a(i)
则(1)、(2)处语句依次是( )
则执行该算法后,i和s的值分别是。
s = "ABCDEF"
For i = 1 To Len(s)
a = Int(Rnd * 3 + 1)
b = Mid(s, a Mod 6 + 1, 1)
ch = ch + Chr(Asc(b) + 32)
Next i
执行该程序后,变量ch的值可能是( )
1)将该字符串内码分成3个字节一组,顺次连接后得到24位二进制数;
2)将得到的24位二进制数字按每6位一组分成4组,每组6个位;
3)在每组数字前补上两个0,得到4个字节的二进制数;
4)将(3)中得到的四个二进制数分别转换为十进制数;
5)将每个十进制数转换为1个加密字符,对应的“密码表”按数值由小到大依次为“ABCDEF GHIJKLMNOPQRSTUV WXYZ-abcdefghijklmnopqrstuvw xyz0123456789+/”
小明按照上述方法,设计了一个字符串(仅包含ASCII字符)加密的VB程序,功能如下:
单击“加密”按钮Command1,程序依次将文本框Text1中每3个字符的ASCII码值作为4个字节转换为四个加密字符,连接这些加密字符,最后在文本框Text2中输出加密结果。
程序运行效果如图所示。
实现上述功能的VB程序如下:
Function Code2Char(c As Integer) As String
Dim s As String
s=“ABCDEFGHIJKLMNOPQRSTU-VWXYZabcdefghijklmnopqrstuvwxyz 0123456789+ /”
Code2Char=
End Function
Private Sub Command1_Click() '加密过程
Dim n As Integer, s As String, i As Integer, ss As String
Dim a1 As Integer , a2 As Integer, a3 As Integer
'存储加密前字符ASCII码
Dim b1 As Integer, b2 As Integer '分别存储分割、转换后的前两个十进制数
Dim b3 As Integer , b4 As Integer '分别存储分割、转换后的后两个十进制数
s= Text1. Text
n= Len(s)
ss=””
For i=1 To n ()
a1= Asc(Mid(s, i, 1))
a2= Asc(Mid(s, i+1, 1))
a3= Asc(Mid(s, i+2, 1))
b1=a1\ 4
b2=(al Mod 4) * 16+(a2 \ 16)
b3=
b4=a3 Mod 64
ss=ss+Code2Char(b1)+Code2Char(b2) + Code2Char( b3)+Code2Char( b4)
Next i
Text2. Text= ss
End Sub