ASP入门（四）-VBScript的流程控制语句
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 %> 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("If ... Then ... 演示
") If Num1 < Num2 Then Response.Write("Num1 < Num2" & "
") '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("If ... Then ... End If 演示
") Response.Write("Num1 < Num2
") End If 'If ... Then ... Else ... End If 演示 Response.Write("If ... Then ... Else ... End If 演示
") If Num1 > Num2 Then Response.Write("Num1 > Num2
") Else Response.Write("Num1 < Num2
") End If 'If ... Then ... ElseIf ... Else ...演示 Response.Write("If ... Then ... ElseIf ... Else ... End If 演示
") If Num1 = Num2 Then Response.Write("Num1 = Num2
") ElseIf Num1 > Num2 Then Response.Write("Num1 > Num2
") Else Response.Write("Num1 < Num2
") End If 'Select Case ... End Select演示返回当天星期几 Response.Write("Select Case演示
") 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 & "") %> body> html>
运行后结果如下显示：
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 %> 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("Do While...Loop
") Response.Write("1+2+3+...+99+100=" & Sum & "
") '--------------------------------------------------------- '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("Do...Loop While
") Response.Write("1+2+3+...+99+100=" & Sum & "
") '--------------------------------------------------------- '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("Do...Loop中使用Exit Do控制
") Response.Write("1+2+3+...+99+100=" & Sum & "
") '--------------------------------------------------------- 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("Do...Loop Until
") Response.Write("1+2+3+...+99+100=" & Sum & "
") '--------------------------------------------------------- 'While ... Wend使用 i = 1 Sum = 0 While i <=100 Sum = Sum + i i = i + 1 Wend Response.Write("While...Wend
") Response.Write("1+2+3+...+99+100=" & Sum & "
") '--------------------------------------------------------- 'For ... Next使用 Sum = 0 For i = 1 To 100 Sum = Sum + i Next Response.Write("For...Next
") Response.Write("1+2+3+...+99+100=" & Sum & "
") '--------------------------------------------------------- '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("For...Next...Step
") Response.Write("1+2+3+...+99+100=" & Sum & "
") '--------------------------------------------------------- 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("For Each...In...Next
") Response.Write("1+2+3+...+99+100=" & Sum & "
") '--------------------------------------------------------- %> body> html>
运行后显示结果如下：
示例代码下载
ASP流程控制语句.RAR