基础问题：两个双引号“""”与“0”的区别？[大概解决了...]
本帖最后由 wsycharles0o 于 2010-8-26 21:44 编辑今天甚是郁闷...
非常郁闷....
发现我纠结了3天的程序就错在这对倒霉的符号上
大家可以试下如下语句：If "" = 0 Then
Msgbox(0,"","就是相等嘛！")
Endif事实证明""和0是等价的
那大家再试下帮助文件中:
TCPRecv()函数的例子程序
把79行的""改成0，
就是那个If $recv <> "" 改成If $recv <> 0
程序就说什么也不工作了....
我做个聊天器，就这一符号，弄得我杯具了三天...
谁能告诉我这""和0到底有啥不同？？？
Ps.TCPRecv()函数的例子程序和TCPSend()函数的例子程序是一对，互相工作：
TCPRecv()函数例子程序:#include <GUIConstantsEx.au3>
Opt('MustDeclareVars', 1)
;==============================================
;==============================================
;SERVER!! Start Me First !!!!!!!!!!!!!!!
;==============================================
;==============================================
Example()
Func Example()
; Set Some reusable info
; Set your Public IP address (@IPAddress1) here.
; Local $szServerPC = @ComputerName
; Local $szIPADDRESS = TCPNameToIP($szServerPC)
Local $szIPADDRESS = @IPAddress1
Local $nPORT = 33891
Local $MainSocket, $GOOEY, $edit, $ConnectedSocket, $szIP_Accepted
Local $msg, $recv,$test=0
; Start The TCP Services
;==============================================
$test=TCPStartup()
MsgBox(0,"","test:"&$test)
; Create a Listening "SOCKET".
; Using your IP Address and Port 33891.
;==============================================
$MainSocket = TCPListen($szIPADDRESS, $nPORT)
MsgBox(0,"TCP","Socket1:"&$MainSocket)
; If the Socket creation fails, exit.
If $MainSocket = -1 Then Exit
; Create a GUI for messages
;==============================================
$GOOEY = GUICreate("My Server (IP: " & $szIPADDRESS & ")", 300, 200)
$edit = GUICtrlCreateEdit("", 10, 10, 280, 180)
GUISetState()
; Initialize a variable to represent a connection
;==============================================
$ConnectedSocket = -1
;Wait for and Accept a connection
;==============================================
Do
$ConnectedSocket = TCPAccept($MainSocket)
Until $ConnectedSocket <> -1
MsgBox(0,"TCP","Socket2:"&$ConnectedSocket)
; Get IP of client connecting
$szIP_Accepted = SocketToIP($ConnectedSocket)
MsgBox(0,"...",$ConnectedSocket)
; GUI Message Loop
;==============================================
While 1
$msg = GUIGetMsg()
; GUI Closed
;--------------------
If $msg = $GUI_EVENT_CLOSE Then ExitLoop
; Try to receive (up to) 2048 bytes
;----------------------------------------------------------------
$recv = TCPRecv($ConnectedSocket, 2048)
; If the receive failed with @error then the socket has disconnected
;----------------------------------------------------------------
If @error Then ExitLoop
; Update the edit control with what we have received
;----------------------------------------------------------------
If $recv <> "" Then GUICtrlSetData($edit, _
$szIP_Accepted & " > " & $recv & @CRLF & GUICtrlRead($edit))
WEnd
If $ConnectedSocket <> -1 Then TCPCloseSocket($ConnectedSocket)
TCPShutdown()
EndFunc ;==>Example
; Function to return IP Address from a connected socket.
;----------------------------------------------------------------------
Func SocketToIP($SHOCKET)
Local $sockaddr, $aRet
$sockaddr = DllStructCreate("short;ushort;uint;char")
$aRet = DllCall("Ws2_32.dll", "int", "getpeername", "int", $SHOCKET, _
"ptr", DllStructGetPtr($sockaddr), "int*", DllStructGetSize($sockaddr))
If Not @error And $aRet = 0 Then
$aRet = DllCall("Ws2_32.dll", "str", "inet_ntoa", "int", DllStructGetData($sockaddr, 3))
If Not @error Then $aRet = $aRet
Else
$aRet = 0
EndIf
$sockaddr = 0
Return $aRet
EndFunc ;==>SocketToIPTCPSend()函数例子程序：Opt('MustDeclareVars', 1)
;==============================================
;==============================================
;CLIENT! Start Me after starting the SERVER!!!!!!!!!!!!!!!
;==============================================
;==============================================
Example()
Func Example()
; Set Some reusable info
;--------------------------
Local $ConnectedSocket, $szData
; Set $szIPADDRESS to wherever the SERVER is. We will change a PC name into an IP Address
; Local $szServerPC = @ComputerName
; Local $szIPADDRESS = TCPNameToIP($szServerPC)
Local $szIPADDRESS = @IPAddress1
Local $nPORT = 33891
MsgBox(0,"TCP TESTING",$szIPADDRESS)
; Start The TCP Services
;==============================================
TCPStartup()
; Initialize a variable to represent a connection
;==============================================
$ConnectedSocket = -1
;Attempt to connect to SERVER at its IP and PORT 33891
;=======================================================
$ConnectedSocket = TCPConnect($szIPADDRESS, $nPORT)
; If there is an error... show it
If @error Then
MsgBox(4112, "Error", "TCPConnect failed with WSA error: " & @error)
; If there is no error loop an inputbox for data
; to send to the SERVER.
Else
;Loop forever asking for data to send to the SERVER
While 1
; InputBox for data to transmit
$szData = InputBox("Data for Server", @LF & @LF & "Enter data to transmit to the SERVER:")
; If they cancel the InputBox or leave it blank we exit our forever loop
If @error Or $szData = "" Then ExitLoop
; We should have data in $szData... lets attempt to send it through our connected socket.
TCPSend($ConnectedSocket, $szData)
; If the send failed with @error then the socket has disconnected
;----------------------------------------------------------------
If @error Then ExitLoop
WEnd
EndIf
EndFunc ;==>Example
纠结纠结，万恶的"" 本帖最后由 xjdjpbp 于 2010-8-25 10:37 编辑
咦？
""不是代表String類的嗎？
0 代表的是Number類的
可能就是因為數據類型不一樣吧＠＠
==============================
DOC的解說 奇怪，我運行了你的代碼
不管79行有沒有改，都是可以運行＠＠
AutoitVersion:3.3.6.1(En)
OS:XP sp3 If '' == 0 Then
MsgBox(0, '', '相等！')
Else
MsgBox(0, '', '不相等！')
EndIf 回复 4# 水木子
斑竹...
是两个双引号... 本帖最后由 xjdjpbp 于 2010-8-25 12:25 编辑
回覆 4# 水木子
我都有一點被搞混了If '' = 0 Then
msgbox(0,'','兩個值相等')
Else
msgbox(0,'','兩個值不相等')
EndIf
If '' == 0 Then
msgbox(0,'','兩個字符串相等')
Else
msgbox(0,'','兩個字符串不相等')
EndIf 「=」跟「==」最大差別差在哪呢？ == 就是进行字符串对比 试试看chr(0) 本帖最后由 水木子 于 2010-8-25 12:42 编辑
回复 5# wsycharles0o
你也可以改成 "" （俩双引号）试试！结果应该是一样的。
单引号只是我的书写习惯。 本帖最后由 wsycharles0o 于 2010-8-25 12:59 编辑
额...改成单等号就相等了...
我晕...单等号的话，chr(0)，0，""都相等
但是改成双等号就都不相等... 我习惯双引号呢! 会不会和变量初定义决定类型有关？
因为我设的那个变量第一次用就是过那个IF语句... 本帖最后由 C.L 于 2010-8-25 23:02 编辑
AU3的数据类型有点混乱
‘’和0 这个不是同一种数据类型，AU3规定，在if中，'=' 是判断两个值是否相等，'=='是判断两个字符串是否相等
1、猜测AU3在处理这个if ' ' = 0 时，因数据类型不同，会将' ' 转换成Number类型，所以 if ' ' = 0 为真，可以测试一下：
if 'abcd' = 0 这一句代码也应该为True，因为：Number（'abcd') = 0
2、猜测AU3在处理这个if ' ' == 0 时，因数据类型不同，会将 0 转换成string类型，string(0) = '0' ,所以 if ' ' == 0 为False 本帖最后由 3mile 于 2010-8-25 23:05 编辑
用代码明下CL兄的意思，个人也感觉AU3的确数据类型有点混乱：bool()
str()
num()
Func bool()
If '' = False Then
MsgBox(0, '', '相等！')
Else
MsgBox(0, '', '不相等！')
EndIf
EndFunc ;==>bool
Func Str()
If '' == '0' Then
MsgBox(0, '', '相等！')
Else
MsgBox(0, '', '不相等！')
EndIf
EndFunc ;==>Str
Func num()
If '' = 0 Then
MsgBox(0, '', '相等！')
Else
MsgBox(0, '', '不相等！')
EndIf
EndFunc ;==>num 额...
大概明了...
算解决吧~
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