VB程序设计基础 申石磊 答案(3)

b! = InputBox(\ c! = InputBox(\ d! = b * b - 4 * a * c

If d >= 0 Then

m! = (-b + Sqr(d)) / (2 * a) n! = (-b - Sqr(d)) / (2 * a) Print \

Else

r = (-b) / (2 * a)

i = Sqr(Abs(-d)) / (2 * a)

Print \

\

End If End Sub

4-5

Private Sub Command1_Click()

Dim x! x = Text1 If x < 60 Then Text2 = \重考！\ ElseIf x < 70 Then Text2 = \及格！\

ElseIf x < 80 Then Text2 = \中等！\ ElseIf x < 90 Then Text2 = \良好！\

Else

Text2 = \优秀！\

End If End Sub

Private Sub Command2_Click()

Text1 = \ Text2 = \ End Sub

4-6

Private Sub Command1_Click()

Dim x! x = Text1 Select Case x Case Is < 60 Text2 = \重考！\

Case Is < 70 Text2 = \及格！\

Case Is < 80

Text2 = \中等！\

Case Is < 90 Text2 = \良好！\

Case Else Text2 = \优秀！\

End Select End Sub

Private Sub Command2_Click()

Text1 = \ Text2 = \ End Sub

4-7

Dim s As String

Private Sub Form_Click() s = InputBox(\请输入年龄\

If s < 30 Then

Print \您的年龄为\请参加长跑运动\

ElseIf s < 40 Then

Print \您的年龄为\请参加跳绳运动\

ElseIf s < 50 Then

Print \您的年龄为\请参加竞走运动\

Else

Print \您的年龄为\请参加慢跑运动\

End If End Sub

4-8

Private Sub Form_Click() For n = 2 To 100 Step 2

Print n;

If n Mod 20 = 0 Then Print

Next n End Sub

4-9

Private Sub Form_click() For n = 100 To 1000

If n Mod 3 = 2 And n Mod 5 = 3 And n Mod 7 = 2

Then Print n;

Next n Print End Sub

4-10

Private Sub Form_click()

m = 0: n = 0

Do

r% = InputBox(\请输入学生成绩\

m = m + r n = n + 1 Loop Until r = -1

Print \学生平均成绩=\

End Sub

4-11

Private Sub Form_click()

Dim a As Integer Dim s As Integer

a = 1 Do

s = s + (-1) ^ (a + 1) * a

a = a + 1

Loop Until a > 100

Print \…+99-100=\

End Sub

4-12

Private Sub Form_Click()

Dim n As Integer Dim m As Integer Dim s As Integer