asp中Byval与Byref的区别

sub Add1(ByVal no as int32) 
no=no+100 
end sub 

sub Add2(ByRef no as int32) 
no=no+100 
end sub 

private sub button1_click(sender as object,e as eventargs)handles button1.click 
dim a as int32 
a=100 
Add1(a) 
msgbox ("a的值为：" & a) '示：a的值为100 
Add2(a) 
msgbox ("a的值为：" & a) '示：a的值为200,因为Add2中的参数no为ByRef,即 
'地址传递，因此在Add2中对no进行修改后，将会导致 
'参数a的值也被修改。 
End Sub 

<SCRIPT LANGUAGE="vbScript"> 
dim a 
a=0 
document.write "a=0" 
document.write "<br/>sub change(byref ar)<br/>" 
change a 
document.write a 
a=0 
document.write "<br/>sub change2(ByVal ar)<br/>" 
change2 a 
document.write a 
a=0 
document.write "<br/>sub change3( ar)<br/>" 
change3 a 
document.write a 
a=0 
document.write "<br/>function change4(byref ar)<br/>" 
change4 a 
document.write a 
a=0 
document.write "<br/>function change5(ByVal ar)<br/>" 
change5 a 
document.write a 
a=0 
document.write "<br/>function change6( ar)<br/>" 
change6 a 
document.write a 
a=0 
sub change(byref ar) 
ar=111 
end sub 
sub change2(ByVal ar) 
ar=222 
end sub 
sub change3( ar) 
ar=333 
end sub 
function change4(byref ar) 
ar=444 
end function 
function change5(ByVal ar) 
ar=555 
end function 
function change6( ar) 
ar=666 
end function 
</SCRIPT> 

<%@LANGUAGE="VBSCRIPT"%> 
<% 
Option Explicit 
'=================================================================== 
' 参数传递 
' 1.值传递参数 (Call By Value) 
' Function TestValue(ByVal A,ByVal B) 
' 函数内参数 A、B 改变 不影响 函数的外部变量 
' 
' 2.指针参数 (Call By Address) 
' Function TestAddress(ByRef A,Byref B) 
' 函数内参数 A、B 改变 影响到 函数的外部变量 
' 
' 说明： 
' 1. 参数可以是数字、字符、数组、对象等VBSCRIPT语言所支持的大部分类型 
' 2. 函数返回值的类型也可以是数字、字符、数组、对象等VBSCRIPT语言所支持的大部分类型 
' 3. 过程调用参数方法与函数类似 
'=================================================================== 
Dim A1,B1 
Dim A2,B2 
Function TestValue(ByVal A,ByVal B) 
A = A + 1 
B = B + 1 
TestValue = A + B 
End Function 
Function TestAddress(ByRef A,Byref B) 
A = A + 1 
B = B + 1 
TestAddress = A + B 
End Function 
A1 = 11 
B1 = 33 
A2 = 11 
B2 = 33 
Response.Write "初值：" & "&nbsp;" 
Response.Write "A1=" & A1 & "&nbsp;" 
Response.Write "B1=" & B1 & "<BR>" 
Response.Write "函数(TestValue)值：" & TestValue(A1,B1) & "<BR>" 
Response.Write "终值：" & "&nbsp;" 
Response.Write "A1=" & A1 & "&nbsp;" 
Response.Write "B1=" & B1 & "<BR><BR><BR>" 
Response.Write "初值：" & "&nbsp;" 
Response.Write "A2=" & A2 & "&nbsp;" 
Response.Write "B2=" & B2 & "<BR>" 
Response.Write "函数(TestAddress)值：" & TestAddress(A2,B2) & "<BR>" 
Response.Write "终值：" & "&nbsp;" 
Response.Write "A2=" & A2 & "&nbsp;" 
Response.Write "B2=" & B2 
'====================== 
' 相似过程 
'====================== 
Sub Test_Value(ByVal A,ByVal B) 
A = A + 1 
B = B + 1 
End Sub 
Sub Test_Address(ByRef A,Byref B) 
A = A + 1 
B = B + 1 
End Sub 
' 类似，传递数组、对象（或者在函数中改变其值、属性） 
'对象直接把对象名作为参数即可 
' 数组，把数组名称作为参数 
redim aryTest(2,2) 
dim intNum 
function Ary_Test(ByRef A) 
Ary_Test = Ubound(Ary_Test,2) 
end function 
'调用 
intNum = Ary_Test(intNum) '值为 3 
%>