全国计算机等级考试VB经典必考资料，知识点总结(7)

“全国计算机等级考试”考试要点

Pointer=i

For j = i+1 To 10 ?每一轮比较几次

If a(Pointer)>a(j) Then Pointer=j

Next j

If i <> Pointer Then

temp=a(i)

a(i)=a(Pointer) a(Pointer)=temp End If Next i

For i =1 To 10

Text1.Text=Text1.Text & a(i) & space(2) Next i

End Sub

方法3：冒泡排序

Private Sub Command1_Click()

Dim a(10) As Integer, i As Integer, j As Integer ,temp As Integer For i= 1 To 10

a(i)=Int(Rnd*90)+10 ?产生10—99之间的随机整数 Next i

For i= 1 To 9 ?比较n-1轮 For j = 1 To 10-i ?每一轮比较几次 If a(j)>a(j+1) Then ?从大到小：a(i)

For i =1 To 10

Text1.Text=Text1.Text & a(i) & space(2) Next i End Sub 七、字符操作

1、字符串取反

例题：在文本框中输入一个字符串，比如：ABCDEFGH，然后反向输出，结果为：HGFEDCBA。

Private Sub Command1_Click()

Dim s As String ,n As Integer ,i As Integer n=Len(Text1.Text )

For i = n To 1 Step-1 ' For i = 1 To n

s = s + Mid(Text1.Text,i,1) ' s = Mid(Text1.Text,i,1) + s Next i Print s

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2013-4-21

“全国计算机等级考试”考试要点

End Sub

2、判断字符串中的某个字符是否为字母

例题：在文本框中输入一个字符串，比如：A$4Ch&*FiyAH，输出字符串中的所有字母，结果为：AChFiyH。

Private Sub Command1_Click()

Dim s As String ,n As Integer ,i As Integer ,c As String n=Len(Text1.Text )

For i = 1 To n

c=Mid(Text1.Text,i,1)

If c >= \ Then s = s + c End If

Next i Print s End Sub

3、统计每类字符的个数

例题：在文本框中输入一个字符串，比如：A$m4Ch&*F13iy%p41H，请分别统计出大写字母、小写字母、数字字符和其他字符的个数。

Private Sub Command1_Click()

Dim n As Integer ,i As Integer ,c As String

Dim n1 As Integer ,n2 As Integer ,n3 As Integer ,n4 As Integer n=Len(Text1.Text )

For i = 1 To n

c=Mid(Text1.Text,i,1) Select Case c