计算机VB第二章课后参考答案

第二章VB程序入门
参考答案：
一、简答题（略）
二、找出以下语句中的错误
1．False --- 错，因为False是VB的关键字或保留字
2．Integers ----- 错，正确的写法是dim x ,y ,z as integer
3．a+b=c 改为c=a+b
4．Mode ---- 错，应改为mod
5．37001 --- 错，因为x取值范围是–32768 ---- 32767
6．÷----- 错，应该写为/
7．.E ---- 错，E的左边必须是有一个数字
8．错，赋值符号的左边字符串缺了双引号
9． 1 --- 错…如是数字1,使用+将会出现”类型不匹配”的错误.如一定要使一字符串与一数字相联,可使用”&”运算符.或用str()函数将数字转换为字符串类型．10．错，可改成如下形式：#01-01-2000#
三、编写语句完成以下任务
1．设这3个数用x、y、z表示，则求3个数乘积的表达式为：x*y*z
如：Dim x as integer,y as integer , z as integer, mul as integer
Mul= x*y*z
2．Option explic it
3．Form1.print “Print Text to The Windows”
4．Dim result as long
Dim x as integer,y as integer , z as integer
Result=(x+y+z)/3
5．Dim x as integer, y as integer, z as integer
6．Y=3*x^5+2*x^4-6*x^3-1
四、数据常量有：”Xname”（字符串型）、True(逻辑型)、517.3(实数型) 、
"2/08/05"（日期时间型）、#1-1#（日期时间型）、
”String”（字符串型）、1（整型）
数据变量有：Xname、Step、X
五、写出下列表达式的值：
1． 6 注: 可用语句Print 2 * 3 ^ 3 mod 4*2 验证, 注意运算符的优先级.
2．2002-1-1 注: 日期数据可进行加减运算
3．xyz123abc
4．xyz123abc
5．12
6．11 注:可用语句x=10 : y=7 : Print y/2*x\3 验证, 优先级相同从左至右进行.
思考为什么会是这个得数.
5 7
-2 -9
False False
程序段2：
Visual
The Demo Basic
实验部分
1. '计算通过inputbox()接受三个数，在窗体上输出'它们的和,乘及平均值.
参考代码：
方法之一:
Private Sub Command1_Click()
Dim a As Single, b As Single,c As Single
a = InputBox("请输入第一个数a：")
b = InputBox("请输入第二个数b：")
c = InputBox("请输入第三个数c：")
Print "a="; a, "b="; b, "c="; c
Print "a + b + c = "; a + b + c
Print "a * b *c ="; a * b * c
Print " a + b + c / 3="; (a + b + c) / 3
End Sub
方法之二:
Private Sub Form_Click()
Dim x As Integer, y As Integer, z As Integer
x = InputBox("请输入：")
y = InputBox("请输入：")
z = InputBox("请输入：")
Print x + y + z
Print x * y * z
Print (x + y + z) / 3
End Sub
2．参考代码和界面如下：
Private Sub Command1_Click()
Dim r As Integer
r = InputBox("请输入圆半径：")
Label1.Caption = 2 * r & " "
Label1.Caption = Label1.Caption & 3.14 * r ^ 2 & " "
Label1.Caption = Label1.Caption & 2 * 3.14 * r
End Sub
r = InputBox("请输入圆半径：")
Label1.Caption = "直径：" & 2 * r
Label1.Caption = Label1.Caption & " 周长：" & 3.14 * r ^ 2
Label1.Caption = Label1.Caption & " 面积：" & 2 * 3.14 * r
End Sub
Private Sub Command3_Click()
End
End Sub
3．参考代码：
Private Sub Form_Click()
Dim a As Integer
a = InputBox("请输入16或33或53...：") …输入的值分别是16，33…..等MsgBox "注意观测！", a, "消息框"
End Sub
思考： a 代表MsgBox中的什么参数？
4．参考代码和界面如下：
方法之一:
Private Sub command1_Click()
Dim temp As Integer
text1.Text = ""
text2.Text = ""
text3.Text = ""
Label4.Caption = "+"
text1.Text = InputBox("请输入第一个数：")
text2.Text = InputBox("请输入第二个数：")
temp = V al(text1.Text) + V al(text2.Text)
text3.Text = temp
End Sub
Private Sub command2_Click()
Dim temp As Integer
text1.Text = ""
text2.Text = ""
text3.Text = ""
Label4.Caption = "-"
text1.Text = InputBox("请输入第一个数：")
text2.Text = InputBox("请输入第二个数：")
temp = V al(text1.Text) - V al(text2.Text)
text3.Text = temp
End Sub
Private Sub Command3_Click()
Dim temp As Integer
text1.Text = ""
text1.Text = InputBox("请输入第一个数：") text2.Text = InputBox("请输入第二个数：") temp = V al(text1.Text) * V al(text2.Text)
text3.Text = temp
End Sub
Private Sub Command4_Click()
Dim temp As Single
text1.Text = ""
text2.Text = ""
text3.Text = ""
Label4.Caption = "/"
text1.Text = InputBox("请输入第一个数：") text2.Text = InputBox("请输入第二个数：") temp = V al(text1.Text) / V al(text2.Text)
text3.Text = temp
End Sub
方法之二:
Private Sub command1_Click()
Dim temp As Integer
text1.Text = ""
Text2.Text = ""
text3.Text = ""
Label4.Caption = Command1.Caption
text1.Text = InputBox("请输入第一个数：") Text2.Text = InputBox("请输入第二个数：") temp = V al(text1.Text) + V al(Text2.Text)
text3.Text = temp
End Sub
Private Sub command2_Click()
Dim temp As Integer
text1.Text = ""
Text2.Text = ""
text3.Text = ""
Label4.Caption = Command2.Caption
text1.Text = InputBox("请输入第一个数：") Text2.Text = InputBox("请输入第二个数：") temp = V al(text1.Text) - V al(Text2.Text)
text3.Text = temp
End Sub
Private Sub Command3_Click()
Dim temp As Integer
text1.Text = ""
Label4.Caption = Command3.Caption
text1.Text = InputBox("请输入第一个数：") Text2.Text = InputBox("请输入第二个数：") temp = V al(text1.Text) * V al(Text2.Text)
text3.Text = temp
End Sub
Private Sub Command4_Click()
Dim temp As Single
text1.Text = ""
Text2.Text = ""
text3.Text = ""
Label4.Caption = Command4.Caption
text1.Text = InputBox("请输入第一个数：") Text2.Text = InputBox("请输入第二个数：") temp = V al(text1.Text) / V al(Text2.Text)
text3.Text = temp
End Sub。