ASP入门(四)-VBScript的流程控制语句 – 瓢虫Monster

VBScript条件语句

我们可以使用四种条件语句

  • If … Then … 语句
  • If … Then … Else 语句
  • If … Then … ElseIf 语句
  • Select … Case 语句

通过下面这段代码(ConditionalStatement.asp)我们演示所有的条件语句用法:

<%@LANGUAGE="VBSCRIPT" CODEPAGE="65001"%>
<% Option Explicit %>
<!– ‘如果使用 Option Explicit,该语句必须出现在脚本的任何其他语句之前。–>
<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>VBScript的条件语句</title>
</head>
<body>
<h1>VBScript的条件语句</h1>
<%
Dim Num1, Num2
Num1
= 10
Num2
= 20
If … Then …当条件为true时执行的语句只有一条
Response.Write("<p><h3>If … Then … 演示</h3>")
If Num1 < Num2 Then Response.Write("Num1 < Num2" & "</p><hr>")

If … Then … End If 当条件为true时执行的语句不止一条时
If Num1 < Num2 Then
Response.Write(
"<p><h3>If … Then … End If 演示</h3>")
Response.Write(
"Num1 < Num2</p><hr>")
End If

If … Then … Else … End If 演示
Response.Write("<p><h3>If … Then … Else … End If 演示</h3>")
If Num1 > Num2 Then
Response.Write(
"Num1 > Num2</p><hr>")
Else
Response.Write(
"Num1 < Num2</p><hr> ")
End If

If … Then … ElseIf … Else …演示
Response.Write("<p><h3>If … Then … ElseIf … Else … End If 演示</h3>")
If Num1 = Num2 Then
Response.Write(
"Num1 = Num2</p><hr>")
ElseIf Num1 > Num2 Then
Response.Write(
"Num1 > Num2</p><hr>")
Else
Response.Write(
"Num1 < Num2</p><hr>")
End If

Select Case … End Select演示返回当天星期几
Response.Write("<p><h3>Select Case演示</h3>")
Dim Week, WeekName
Week
= WeekDay(date) 获取现在是星期几
Select Case Week
Case 1
WeekName
= "Sleepy Sunday"
Case 2
WeekName
= "Monday again!"
Case 3
WeekName
= "Just Tuesday!"
Case 4
WeekName
= "Wednesday!"
Case 5
WeekName
= "Thursday…"
Case 6
WeekName
= "Finally Friday!"
Case 7
WeekName
= "Super Saturday!!!!"
End Select
Response.Write(WeekName
& "</p>")
%>
</body>
</html>

运行后结果如下显示:

20150810003

VBScript循环语句

在VBScript中,我们可以四种循环语句

  • For…Next 运行制定次数的一段代码
  • For Each…Next 针对集合中的每个项目或者数组中的每个元素来运行某段代码
  • Do…Loop 当条件为true(While)或者直到条件为true(Until
  • While…Wend 不要使用这个语句,请用Do…Loop代替

同样,本人写一段大代码(LoopStatement.asp)来展示循环语句的使用,代码的主要功能是计算1到100相加的计算。

<%@LANGUAGE="VBSCRIPT" CODEPAGE="65001"%>
<% Option Explicit %>
<!– ‘如果使用 Option Explicit,该语句必须出现在脚本的任何其他语句之前。–>
<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>VBScript的循环语句</title>
</head>
<body>
<h1>VBScript的循环语句</h1>
<%
Dim i, Sum
Do While … Loop循环
i = 1
Sum
= 0
计算1到100相加的结果
Do While i <= 100 先判断,在循环
Sum = Sum + i
i
= i + 1
Loop
Response.Write(
"<b>Do While…Loop</b><br>")
Response.Write(
"1+2+3+…+99+100=" & Sum & "<hr>")
———————————————————
Do…Loop While循环使用
i = 1
Sum
= 0
Do
Sum
= Sum + i
i
= i + 1
Loop While i <= 100 先循环,再判断
Response.Write("<b>Do…Loop While</b><br>")
Response.Write(
"1+2+3+…+99+100=" & Sum & "<hr>")
———————————————————
Exit Do的使用
i = 1
Sum
= 0
Do
If i > 100 Then Exit Do 当i>100时退出Do循环
Sum = Sum + i
i
= i + 1
Loop
Response.Write(
"<b>Do…Loop中使用Exit Do控制</b><br>")
Response.Write(
"1+2+3+…+99+100=" & Sum & "<hr>")
———————————————————
i = 1
Sum
= 0
Do
Sum
= Sum + i
i
= i + 1
Loop Until i > 100 直到i>100,停止循环
Response.Write("<b>Do…Loop Until</b><br>")
Response.Write(
"1+2+3+…+99+100=" & Sum & "<hr>")
———————————————————
While … Wend使用
i = 1
Sum
= 0
While i <=100
Sum
= Sum + i
i
= i + 1
Wend
Response.Write(
"<b>While…Wend</b><br>")
Response.Write(
"1+2+3+…+99+100=" & Sum & "<hr>")
———————————————————
For … Next使用
Sum = 0
For i = 1 To 100
Sum
= Sum + i
Next
Response.Write(
"<b>For…Next</b><br>")
Response.Write(
"1+2+3+…+99+100=" & Sum & "<hr>")
———————————————————
分别计算1到100的奇数和偶数的和,最后奇数和偶数相加就是最终结果
Dim OddSum 奇数和
Dim EvenSum 偶数和
OddSum = 0
EvenSum
= 0
For i = 1 To 100 Step 2
OddSum
= OddSum + i
Next
For i = 0 To 1000 Step 2
If i > 100 Then Exit For 当i>100时,退出For循环
EvenSum = EvenSum + i
Next
Sum
= EvenSum + OddSum
Response.Write(
"<b>For…Next…Step</b><br>")
Response.Write(
"1+2+3+…+99+100=" & Sum & "<hr>")
———————————————————
Dim Num(100) 声明101个元素的数组Num
For i = 0 To 100
Num(i)
= i 赋值,Num(0)=0, Num(1)=1,…,Num(100)=100
Next
Sum
= 0
Dim Nums
For Each Nums In Num 遍历数组每个元素
Sum = Sum + Nums
Next
Response.Write(
"<b>For Each…In…Next</b><br>")
Response.Write(
"1+2+3+…+99+100=" & Sum & "<hr>")
———————————————————
%>
</body>
</html>

运行后显示结果如下:

20150810004

示例代码下载

ASP流程控制语句.RAR

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