这道题怎么解(重复)

[cqyl1012]

Sub P1(X As Integer,Byval y As Integer)
Dim z As Integer
Z=X
X=Y
Y=X
End Sub
Private Sub Command1_Click( )
Dim m As Integer, n As Integer
M=5
N=20
P1 M,N
Print “m=”; m; “n=”;n
为什么程序运行后结果为:m=20 n=20,请详解,谢谢各位老师!

[online]

看着是个两个数交换，好像又不是
设置断点跟踪，这样你可以看到变量的变化

[yinweihong]

你要什么样的结果？
Sub P1(X As Integer,y As Integer)
Dim z As Integer
Z=X
X=Y
Y=z
End Sub

[northwolves]

Sub P1(X As Integer,Byval y As Integer)
Dim z As Integer
Z=X
X=Y
Y=X '------------->改为 y=z
End Sub

[pigpag]

改错题？还是解释题？

[捏造的信仰]

第一个参数前面没有byval啦，加上去就行了
byval是按值传递 VB里面默认是按引用传递