Question

VB程序设计习题

函数y的表达式如下
y=|x| x<10
y2=3x-1 10<=x<=20
y=3x+2 x>20
编写程序，当输入x的值后计算输出y的值分别用以下语句编写：多个单分支的If语句、一个多分支的If语句和Select Case语句

Answer 1

1.
x = Val(InputBox("Input X: "))
If x < 10 Then y = Abs(x)
If x <= 20 Then y = Sqr(3 * x - 1)
If x > 20 Then y = 3 * x + 2
Debug.Print y

2.
x = Val(InputBox("Input X: "))
If x < 10 Then
y = Abs(x)
ElseIf x <= 20 Then y = Sqr(3 * x - 1)
ElseIf x > 20 Then y = 3 * x + 2
End If
Debug.Print y

3.
x = Val(InputBox("Input X: "))
select case x
case x < 10
y = Abs(x)
case <= 20
y = Sqr(3 * x - 1)
case else
y = 3 * x + 2
end select
Debug.Print y

Answer 2

1
x=val(inputbox("输入:"))
if x<10 then y=abs(x)
if x>=10 and x<=20 then y=3*x-1
if x>20 then y=3*x+2
?y

2
if x<10 then
y=abs(x)
elseif x<=20 then
y=3*x-1
else
y=3*x+2
endif
?y

3
select case x
case is<10
y=abs(x)
case 10 to 20
y=3*x-1
case else
y=3*x+2
end select
?y

Answer 3

(1) if
endif
if
endif
if
endif
(2)if
else if
else
endif
(3)select case x