按值传递与按地址传递
1. 按值传递参数数组
按值传递参数时，是将实在参数的值复制一个形式参数中，若是在调用过程当中改变了形式参数的值，不会影响实在参数自己，即实在参数保持调用前的值不变。spa
按值传递参数方法是在形式参数前加上ByVal，如：Sub S1(ByVal a As Integer，ByVal b As integer) ；另一些特别状况也是按值传递参数，如实在参数是常数、表达式时； 对于实在参数是变量时，只要在其左右加上圆括号，如 Call Sub1((x),(y))。3d
2.按地址传递参数orm
按地址传递参数时，把实在参数的地址传送给被调用过程，形式参数和实在参数共用内存的同一地址。在被调用过程当中，形式参数的值一旦改变，相应实参的值也跟着改变。blog
按地址传递参数方法是在形式参数前加上ByRef，或形式参数前为空，如：Sub S1([ByRef] a As Integer，[ByRef] b As integer) ；形参数组只能按地址传递参数。内存
举例1：博客
Private Sub Form_Click()
Dim a As Integer, b As Integer
a = 10: b = 25
Call sub1(a, b)
Print a, b
End Sub变量
Private Sub sub1(ByVal m As Integer, ByVal n As Integer)
Dim temp As Integer
temp = m
m = n
n = temp
Print m, n, temp
End Sub方法
运行结果是：im
在窗体第一行显示：25 10 10
在窗体第二行显示：10 25
见下图：
举例2：
Private Sub Form_Click()
Dim a As Integer, b As Integer
a = 10: b = 25
Call sub1(a, b)
Print a, b
End Sub
Private Sub sub1(ByVal m As Integer, n As Integer)
Dim temp As Integer
temp = m
m = n
n = temp
Print m, n, temp
End Sub
运行结果是：
在窗体第一行显示：25 10 10
在窗体第二行显示：10 10
见下图：
Private Sub Form_Click()
Dim a As Integer, b As Integer
a = 10: b = 25
Call sub1(a, b)
Print a, b
End Sub
Private Sub sub1(m As Integer, ByVal n As Integer)
Dim temp As Integer
temp = m
m = n
n = temp
Print m, n, temp
End Sub
运行结果是：
在窗体第一行显示：25 10 10
在窗体第二行显示：25 25
见下图：
举例4：
Private Sub Form_Click()
Dim a As Integer, b As Integer
a = 10: b = 25
Call sub1(a, b)
Print a, b
End Sub
Private Sub sub1(m As Integer, n As Integer)
Dim temp As Integer
temp = m
m = n
n = temp
Print m, n, temp
End Sub
运行结果是：
在窗体第一行显示：25 10 10
在窗体第二行显示：25 10
见下图：
Private Sub Form_Click()
Dim a As Integer, b As Integer
a = 20: b = 50
p1 a, b
p2 a, b
p3 a, b
Print "a="; a, "b="; b
End Sub
Private Sub p1(x As Integer, ByVal y As Integer)
x = x + 10
y = y + 20
End Sub
Private Sub p2(ByVal x As Integer, y As Integer)
x = x + 10
y = y + 20
End Sub
Private Sub p3(ByVal x As Integer, ByVal y As Integer)
x = x + 10
y = y + 20
End Sub
运行结果是：
在窗体上显示：a= 30 b=70
见下图：