reg.htm

常用正则表达式 整理篇_正则表达式_常用正则表达式 整理篇_正则表达式

<DIV class=hl-main><SPAN style="COLOR: gray">^</SPAN><SPAN style="COLOR: olive">[</SPAN><SPAN style="COLOR: blue">A</SPAN><SPAN style="COLOR: gray">-</SPAN><SPAN style="COLOR: blue">Za</SPAN><SPAN style="COLOR: gray">-</SPAN><SPAN style="COLOR: blue">z0</SPAN><SPAN style="COLOR: gray">-</SPAN><SPAN style="COLOR: maroon">9</SPAN><SPAN style="COLOR: olive">]</SPAN><SPAN style="COLOR: gray">+$</SPAN></DIV></DIV>
<P>匹配由数字、26个英文字母或者下划线组成的字符串</P>
<DIV class=hl-surround>
<DIV class=hl-main><SPAN style="COLOR: gray">^\</SPAN><SPAN style="COLOR: blue">w</SPAN><SPAN style="COLOR: gray">+$</SPAN></DIV></DIV>
<P>匹配email地址</P>
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<DIV class=hl-main><SPAN style="COLOR: gray">^</SPAN><SPAN style="COLOR: olive">[</SPAN><SPAN style="COLOR: gray">\</SPAN><SPAN style="COLOR: blue">w</SPAN><SPAN style="COLOR: gray">-</SPAN><SPAN style="COLOR: olive">]</SPAN><SPAN style="COLOR: gray">+</SPAN><SPAN style="COLOR: olive">(</SPAN><SPAN style="COLOR: gray">\.</SPAN><SPAN style="COLOR: olive">[</SPAN><SPAN style="COLOR: gray">\</SPAN><SPAN style="COLOR: blue">w</SPAN><SPAN style="COLOR: gray">-</SPAN><SPAN style="COLOR: olive">]</SPAN><SPAN style="COLOR: gray">+</SPAN><SPAN style="COLOR: olive">)</SPAN><SPAN style="COLOR: gray">*@</SPAN><SPAN style="COLOR: olive">[</SPAN><SPAN style="COLOR: gray">\</SPAN><SPAN style="COLOR: blue">w</SPAN><SPAN style="COLOR: gray">-</SPAN><SPAN style="COLOR: olive">]</SPAN><SPAN style="COLOR: gray">+</SPAN><SPAN style="COLOR: olive">(</SPAN><SPAN style="COLOR: gray">\.</SPAN><SPAN style="COLOR: olive">[</SPAN><SPAN style="COLOR: gray">\</SPAN><SPAN style="COLOR: blue">w</SPAN><SPAN style="COLOR: gray">-</SPAN><SPAN style="COLOR: olive">]</SPAN><SPAN style="COLOR: gray">+</SPAN><SPAN style="COLOR: olive">)</SPAN><SPAN style="COLOR: gray">+$</SPAN></DIV></DIV>
<P>匹配url</P>
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<DIV class=hl-main><SPAN style="COLOR: gray">^</SPAN><SPAN style="COLOR: olive">[</SPAN><SPAN style="COLOR: blue">a</SPAN><SPAN style="COLOR: gray">-</SPAN><SPAN style="COLOR: blue">zA</SPAN><SPAN style="COLOR: gray">-</SPAN><SPAN style="COLOR: blue">z</SPAN><SPAN style="COLOR: olive">]</SPAN><SPAN style="COLOR: gray">+:</SPAN><SPAN style="COLOR: #ffa500">//匹配(\w+(-\w+)*)(\.(\w+(-\w+)*))*(\?\S*)?$</SPAN></DIV></DIV>
<P>匹配html tag</P>
<DIV class=hl-surround>
<DIV class=hl-main><SPAN style="COLOR: gray">&lt;\</SPAN><SPAN style="COLOR: blue">s</SPAN><SPAN style="COLOR: gray">*</SPAN><SPAN style="COLOR: olive">(</SPAN><SPAN style="COLOR: gray">\</SPAN><SPAN style="COLOR: blue">S</SPAN><SPAN style="COLOR: gray">+</SPAN><SPAN style="COLOR: olive">)(</SPAN><SPAN style="COLOR: gray">\</SPAN><SPAN style="COLOR: blue">s</SPAN><SPAN style="COLOR: olive">[</SPAN><SPAN style="COLOR: gray">^&gt;</SPAN><SPAN style="COLOR: olive">]</SPAN><SPAN style="COLOR: gray">*</SPAN><SPAN style="COLOR: olive">)</SPAN><SPAN style="COLOR: gray">?&gt;</SPAN><SPAN style="COLOR: olive">(</SPAN><SPAN style="COLOR: gray">.*?</SPAN><SPAN style="COLOR: olive">)</SPAN><SPAN style="COLOR: gray">&lt;\</SPAN><SPAN style="COLOR: blue">s</SPAN><SPAN style="COLOR: gray">*\</SPAN><SPAN style="COLOR: #8b0000">/</SPAN><SPAN style="COLOR: red">\1\s*&gt;</SPAN></DIV></DIV>
<P>Visual Basic & C# Regular Expression<BR>1.确认有效电子邮件格式<BR>下面的示例使用静态 Regex.IsMatch 方法验证一个字符串是否为有效电子邮件格式。如果字符串包含一个有效的电子邮件地址，则 IsValidEmail 方法返回 true，否则返回 false，但不采取其他任何操作。您可以使用 IsValidEmail，在应用程序将地址存储在数据库中或显示在 ASP.NET 页中之前，筛选出包含无效字符的电子邮件地址。</P>
<P>[Visual Basic]</P>
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<DIV class=hl-main>Function IsValidEmail(strIn As String) As Boolean<BR>' Return true if strIn is in valid e-mail format.<BR>Return Regex.IsMatch(strIn, ("^([\w-\.]+)@((\[[0-9]{ 1,3 }\.[0-9]{ 1,3 }\.[0-9]{ 1,3 }\.)|(([\w-]+\.)+))([a-zA-Z]{ 2,4 }|[0-9]{ 1,3 })(\]?)$")<BR>End Function</DIV></DIV>
<P>[C#]</P>
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<DIV class=hl-main>bool IsValidEmail(string strIn)<BR>{<BR>// Return true if strIn is in valid e-mail format.<BR>return Regex.IsMatch(strIn, @"^([\w-\.]+)@((\[[0-9]{ 1,3 }\.[0-9]{ 1,3 }\.[0-9]{ 1,3 }\.)|(([\w-]+\.)+))([a-zA-Z]{ 2,4 }|[0-9]{ 1,3 })(\]?)$");<BR>}</DIV></DIV>
<P>2.清理输入字符串<BR>下面的代码示例使用静态 Regex.Replace 方法从字符串中抽出无效字符。您可以使用这里定义的 CleanInput 方法，清除掉在接受用户输入的窗体的文本字段中输入的可能有害的字符。CleanInput 在清除掉除 @、-（连字符）和 .（句点）以外的所有非字母数字字符后返回一个字符串。</P>
<P>[Visual Basic]</P>
<DIV class=hl-surround>
<DIV class=hl-main>Function CleanInput(strIn As String) As String<BR>' Replace invalid characters with empty strings.<BR>Return Regex.Replace(strIn, "[^\w\.@-]", "")<BR>End Function</DIV></DIV>
<P>[C#]</P>
<DIV class=hl-surround>
<DIV class=hl-main>String CleanInput(string strIn)<BR>{<BR>    // Replace invalid characters with empty strings.<BR>    return Regex.Replace(strIn, @"[^\w\.@-]", "");<BR>}</DIV></DIV>
<P>3.更改日期格式<BR>以下代码示例使用 Regex.Replace 方法来用 dd-mm-yy 的日期形式代替 mm/dd/yy 的日期形式。</P>
<P>[Visual Basic]</P>
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<DIV class=hl-main>Function MDYToDMY(input As String) As String<BR>Return Regex.Replace(input, _<BR>"\b(?&lt;month&gt;\d{ 1,2 })/(?&lt;day&gt;\d{ 1,2 })/(?&lt;year&gt;\d{ 2,4 })\b", _<BR>"${ day }-${ month }-${ year }")<BR>End Function</DIV></DIV>
<P>[C#]</P>
<DIV class=hl-surround>
<DIV class=hl-main>String MDYToDMY(String input)<BR>{<BR>    return Regex.Replace(input,"\\b(?&lt;month&gt;\\d{ 1,2 })/(?&lt;day&gt;\\d{ 1,2 })/(?&lt;year&gt;\\d{ 2,4 })\\b","${ day }-${ month }-${ year }");<BR>}</DIV></DIV>
<P>Regex 替换模式<BR>本示例说明如何在 Regex.Replace 的替换模式中使用命名的反向引用。其中，替换表达式 ${ day } 插入由 (?…) 组捕获的子字符串。</P>
<P>有几种静态函数使您可以在使用<a href="http://www.jb51.net/list/list_6_1.htm" target="_blank"><font color=red>正则</font></a>表达式操作时无需创建显式<a href="http://www.jb51.net/list/list_6_1.htm" target="_blank"><font color=red>正则</font></a>表达式对象，而 Regex.Replace 函数正是其中之一。如果您不想保留编译的<a href="http://www.jb51.net/list/list_6_1.htm" target="_blank"><font color=red>正则</font></a>表达式，这将给您带来方便</P>
<P>4.提取 URL 信息<BR>以下代码示例使用 Match.Result 来从 URL 提取协议和端口号。例如，“http://www.penner.cn:8080……将返回“http:8080”。</P>
<P>[Visual Basic]</P>
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<DIV class=hl-main>Function Extension(url As String) As String<BR>Dim r As New Regex("^(?&lt;proto&gt;\w+)://[^/]+?(?&lt;port&gt;:\d+)?/", _<BR>RegexOptions.Compiled)<BR>Return r.Match(url).Result("${ proto }${ port }")<BR>End Function</DIV></DIV>
<P>[C#]</P>
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<DIV class=hl-main>String Extension(String url)<BR>{<BR>    Regex r = new Regex(@"^(?&lt;proto&gt;\w+)://[^/]+?(?&lt;port&gt;:\d+)?/",<BR>    RegexOptions.Compiled);<BR>    return r.Match(url).Result("${ proto }${ port }");<BR>}</DIV></DIV>
<P>只有字母和数字，不小于6位，且数字字母都包含的密码的<a href="http://www.jb51.net/list/list_6_1.htm" target="_blank"><font color=red>正则</font></a>表达式<BR>在C#中，可以用这个来表示：</P>
<DIV class=hl-surround>
<DIV class=hl-main><SPAN style="COLOR: #8b0000">"</SPAN><SPAN style="COLOR: red">\w{ 6 }(\w+)*</SPAN><SPAN style="COLOR: #8b0000">"</SPAN></DIV></DIV>
<P>一个将需要将路径字符串拆分为根目录和子目录两部分的算法程序，考虑路径格式有：C:\aa\bb\cc ，\\aa\bb\cc ， ftp://aa.bb/cc 上述路径将分别被拆分为：C:\和aa\bb\cc ，\\aa 和 \bb\cc ， ftp:// 和 aa.bb/cc 用javascript实现如下：</P>
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<DIV class=hl-main><SPAN style="COLOR: green">var</SPAN><SPAN style="COLOR: gray"> </SPAN><SPAN style="COLOR: blue">strRoot</SPAN><SPAN style="COLOR: gray">,</SPAN><SPAN style="COLOR: blue">strSub</SPAN><SPAN style="COLOR: gray"><BR></SPAN><SPAN style="COLOR: green">var</SPAN><SPAN style="COLOR: gray"> </SPAN><SPAN style="COLOR: blue">regPathParse</SPAN><SPAN style="COLOR: gray">=</SPAN><SPAN style="COLOR: #8b0000">/</SPAN><SPAN style="COLOR: red">^([^\\^</SPAN><SPAN style="COLOR: navy">\/</SPAN><SPAN style="COLOR: red">]+[\\</SPAN><SPAN style="COLOR: navy">\/</SPAN><SPAN style="COLOR: red">]+|\\\\[^\\]+)(.*)$</SPAN><SPAN style="COLOR: #8b0000">/</SPAN><SPAN style="COLOR: gray"><BR></SPAN><SPAN style="COLOR: green">if</SPAN><SPAN style="COLOR: olive">(</SPAN><SPAN style="COLOR: blue">regPathParse</SPAN><SPAN style="COLOR: gray">.</SPAN><SPAN style="COLOR: blue">test</SPAN><SPAN style="COLOR: olive">(</SPAN><SPAN style="COLOR: blue">strFolder</SPAN><SPAN style="COLOR: olive">))</SPAN><SPAN style="COLOR: gray"><BR></SPAN><SPAN style="COLOR: olive">{</SPAN><SPAN style="COLOR: gray"><BR>    </SPAN><SPAN style="COLOR: blue">strRoot</SPAN><SPAN style="COLOR: gray">=</SPAN><SPAN style="COLOR: teal">RegExp</SPAN><SPAN style="COLOR: gray">.$</SPAN><SPAN style="COLOR: maroon">1</SPAN><SPAN style="COLOR: gray"><BR>    </SPAN><SPAN style="COLOR: blue">strSub</SPAN><SPAN style="COLOR: gray">=</SPAN><SPAN style="COLOR: teal">RegExp</SPAN><SPAN style="COLOR: gray">.$</SPAN><SPAN style="COLOR: maroon">2</SPAN><SPAN style="COLOR: gray"><BR></SPAN><SPAN style="COLOR: olive">}</SPAN></DIV></DIV>
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