Use a negative [look-ahead][1] that asserts the absence of any of the three words somewhere in the input:

    ^(?!.*(trunk|tags|branches)).*$

I also slightly rearranged your regex to correct minor errors.

  [1]: http://www.regular-expressions.info/lookaround.html

Use a &quot;standard&quot; match and look for `!IsMatch`

    var exp = new Regex(@&quot;trunk|tags|branches&quot;);
    var result = !exp.IsMatch(&quot;trunk/blah/blah&quot;);

Why persons love to make their life difficult?

Ah... And remember the `ass` principle! http://www.codinghorror.com/blog/2008/10/obscenity-filters-bad-idea-or-incredibly-intercoursing-bad-idea.html

So it would be better to write

    var exp = new Regex(@&quot;\b(trunk|tags|branches)\b&quot;);

But if you really need a negative lookahed expression, and keeping up with the `ass` principle

    var exp = new Regex(@&quot;^(?!.*\b(trunk|tags|branches)\b)&quot;;

Tester: http://gskinner.com/RegExr/?2uv1g

I&#39;ll note that if you are looking for full paths (words separated by `/` or `\`) then

    var exp = new Regex(@&quot;^(?!.*(^|\\|/)(trunk|tags|branches)(/|\\|$))&quot;;

Tester: http://gskinner.com/RegExr/?2uv1p


When should we use + for concatenation of strings, when is StringBuilder preferred and When is it suitable to use concat.

I&#39;ve heard StringBuilder is preferable for concatenation within loops. Why is it so?

Thanks.

String concatenation in Java - when to use +, StringBuilder and concat

I have tried to different ways to clear a form:

    &lt;form action=&quot;service.php&quot; id=&quot;addRunner&quot; name=&quot;addRunner&quot; method=&quot;post&quot;&gt;
    First Name: &lt;input type=&quot;text&quot; name=&quot;txtFirstName&quot; id=&quot;txtFirstName&quot; /&gt;&lt;br /&gt;
    Last Name:  &lt;input type=&quot;text&quot; name=&quot;txtLastName&quot; id=&quot;txtLastName&quot; /&gt;&lt;br /&gt;
    Gender: &lt;select id=&quot;ddlGender&quot; name=&quot;ddlGender&quot;&gt;&lt;option value=&quot;&quot;&gt;--Please Select--&lt;/option&gt;
    &lt;option value=&quot;f&quot;&gt;Female&lt;/option&gt;
    &lt;option value=&quot;m&quot;&gt;Male&lt;/option&gt;
    &lt;/select&gt;&lt;br /&gt;
    Finish Time:
    &lt;input type=&quot;text&quot; name=&quot;txtMinutes&quot; id=&quot;txtMinutes&quot; size=&quot;10&quot; maxlength=&quot;2&quot;&gt;(Minutes)
    &lt;input type=&quot;text&quot; name=&quot;txtSeconds&quot; id=&quot;txtSeconds&quot; size=&quot;10&quot; maxlength=&quot;2&quot;&gt;(Seconds)
    &lt;br /&gt;
    &lt;button type=&quot;submit&quot; name=&quot;btnSave&quot; id=&quot;btnSave&quot;&gt;Add Runner&lt;/button&gt;
    &lt;input type=&quot;hidden&quot; name=&quot;action&quot; value=&quot;addRunner&quot; id=&quot;action&quot;&gt;
    &lt;/form&gt;

jQuery #1:

    function clearInputs(){
    $(&quot;#txtFirstName&quot;).val(&#39;&#39;);
    $(&quot;#txtLastName&quot;).val(&#39;&#39;);
    $(&quot;#ddlGender&quot;).val(&#39;&#39;);
    $(&quot;#txtMinutes&quot;).val(&#39;&#39;);
    $(&quot;#txtSeconds&quot;).val(&#39;&#39;);
    }

This works perfectly.

jQuery #2:

    function clearInputs(data){
    $(&quot;#addRunner :input&quot;).each(function(){
    $(this).val(&#39;&#39;);
    });

This clears the form but does not let me submit any more any information to it. I try and click the button again and it does nothing.

Here&#39;s the button click handler:

	$(&quot;#btnSave&quot;).click(function(){
		var data = $(&quot;#addRunner :input&quot;).serializeArray();
		$.post($(&quot;#addRunner&quot;).attr(&#39;action&#39;), data, function(json){
			if (json.status == &quot;fail&quot;){
				alert(json.message);
			}
			if (json.status == &quot;success&quot;){
				alert(json.message);
				clearInputs();
			}
		}, &quot;json&quot;);
	});

PHP Post code:

    &lt;?php
    if($_POST){	
	    if ($_POST[&#39;action&#39;] == &#39;addRunner&#39;) {
		    $fname = htmlspecialchars($_POST[&#39;txtFirstName&#39;]);
		    $lname = htmlspecialchars($_POST[&#39;txtLastName&#39;]);
		    $gender = htmlspecialchars($_POST[&#39;ddlGender&#39;]);
		    $minutes = htmlspecialchars($_POST[&#39;txtMinutes&#39;]);
		    $seconds = htmlspecialchars($_POST[&#39;txtSeconds&#39;]);
		    if(preg_match(&#39;/[^\w\s]/i&#39;, $fname) || preg_match(&#39;/[^\w\s]/i&#39;, $lname)) {
			    fail(&#39;Invalid name provided.&#39;);
		    }
		    if( empty($fname) || empty($lname) ) {
		    	    fail(&#39;Please enter a first and last name.&#39;);
		    }
		    if( empty($gender) ) {
			    fail(&#39;Please select a gender.&#39;);
		    }
		    if( empty($minutes) || empty($seconds) ) {
			    fail(&#39;Please enter minutes and seconds.&#39;);
		    }
		    $time = $minutes.&quot;:&quot;.$seconds;

		$query = &quot;INSERT INTO runners SET first_name=&#39;$fname&#39;, last_name=&#39;$lname&#39;, gender=&#39;$gender&#39;, finish_time=&#39;$time&#39;&quot;;
		$result = db_connection($query);
		
		if ($result) {
			$msg = &quot;Runner: &quot;.$fname.&quot; &quot;.$lname.&quot; added successfully&quot; ;
			success($msg);
		} else {
			fail(&#39;Insert failed.&#39;);
		}
		exit;
	}
} 

If I use jQuery method #2, I get this error in the console:

    Uncaught TypeError: Cannot read property &#39;status&#39; of null

Why does this happen?

I forgot to include this key information:

    function fail ($message){
		die(json_encode(array(&#39;status&#39;=&gt;&#39;fail&#39;, &#39;message&#39;=&gt;$message)));
	}
	
    function success ($message){
		die(json_encode(array(&#39;status&#39;=&gt;&#39;success&#39;, &#39;message&#39;=&gt;$message)));

This sends the message back to the AJAX function in jQuery. It looks like after I submit the form once using method #2 the success/fail messages are blanked out.

jQuery: Clearing Form Inputs

I&#39;m trying to put together a regex to find when specific words *don&#39;t* exist in a string. Specifically, I want to know when &quot;trunk&quot;, &quot;tags&quot; or &quot;branches&quot; doesn&#39;t exist (this is for a Subversion pre-commit hook). Based on the [Regular expression to match string not containing a word][1] answer I can easily do this for one word using negative look-arounds:

    ^((?!trunk).)*$

It&#39;s the &quot;and&quot; operator I&#39;m struggling with and I can&#39;t seem to get combinations including the other two words working.

This is running fine in .NET with a single word:

    var exp = new Regex(@&quot;^((?!trunk).)*$&quot;);
    exp.IsMatch(&quot;trunk/blah/blah&quot;);

It will return false as it currently stands or true if &quot;trunk&quot; doesn&#39;t exist in the path on the second line.

What am I missing here?

  [1]: https://stackoverflow.com/questions/406230/regular-expression-to-match-string-not-containing-a-word

Regex for string not containing multiple specific words

I'm trying to put together a regex to find when specific words don't exist in a string. Specifically, I want to know when "trunk", "tags" or "branches" doesn't exist (this is for a Subversion pre-commit hook). Based on the <a href="https://stackoverflow.com/questions/406230/regular-expression-to-match-string-not-containing-a-word" target="_blank" rel="noopener noreferrer">Regular expression to match string not containing a word</a> answer I can easily do this for one word using negative look-arounds:
<pre><code class="hljs language-ruby">^((?!trunk).)*$
</code></pre>
It's the "and" operator I'm struggling with and I can't seem to get combinations including the other two words working.
This is running fine in .NET with a single word:
<pre><code class="hljs language-ini">var exp = new Regex(@"^((?!trunk).)*$");
exp.IsMatch("trunk/blah/blah");
</code></pre>
It will return false as it currently stands or true if "trunk" doesn't exist in the path on the second line.
What am I missing here?

While using the `using() {}` (sic) blocks as shown below, and assuming that `cmd1` does not live beyond the scope of the first `using() {}` block, why should the second block throw an exception with the message 

&gt; The SqlParameter is already contained by another SqlParameterCollection

Does it mean that resources and/or handles - including the parameters (`SqlParameterCollection`) - attached to `cmd1` are not released when its destroyed at the end of the block?

    using (var conn = new SqlConnection(&quot;Data Source=.;Initial Catalog=Test;Integrated Security=True&quot;))
    {
        var parameters = new SqlParameter[] { new SqlParameter(&quot;@ProductId&quot;, SqlDbType.Int ) };

        using(var cmd1 = new SqlCommand(&quot;SELECT ProductName FROM Products WHERE ProductId = @ProductId&quot;))
        {
            foreach (var parameter in parameters)
            {
                cmd1.Parameters.Add(parameter);                
            }
            // cmd1.Parameters.Clear(); // uncomment to save your skin!
        }

        using (var cmd2 = new SqlCommand(&quot;SELECT Review FROM ProductReviews WHERE ProductId = @ProductId&quot;))
        {
            foreach (var parameter in parameters)
            {
                cmd2.Parameters.Add(parameter);
            }
        }
    }


**NOTE:** Doing cmd1.Parameters.Clear() just before the last brace of the first **using() {}** block will save you from the exception (and possible embarrassment).

If you need to reproduce you can use the following scripts to create the objects:

    CREATE TABLE Products
    (
        ProductId int IDENTITY(1,1) NOT NULL PRIMARY KEY CLUSTERED,
        ProductName nvarchar(32) NOT NULL
    )
    GO

    CREATE TABLE ProductReviews
    (
        ReviewId int IDENTITY(1,1) NOT NULL PRIMARY KEY CLUSTERED,
        ProductId int NOT NULL,
        Review nvarchar(128) NOT NULL
    )
    GO


The SqlParameter is already contained by another SqlParameterCollection - Does using() {} cheat?

From a [press release][1] yesterday on InfoWorld regarding the new [Microsoft Roslyn][2]:

&gt; The most obvious advantage of this kind of &quot;deconstructed&quot; compiler is
&gt; that it allows the entire compile-execute process to be invoked from
&gt; within .Net applications. Hejlsberg demonstrated a C# program that
&gt; passed a few code snippets to the C# compiler as strings; the compiler
&gt; returned the resulting IL assembly code as an object, which was then
&gt; passed to the Common Language Runtime (CLR) for execution. Voil&#224;! With
&gt; Roslyn, C# gains a dynamic language&#39;s ability to generate and invoke
&gt; code at runtime.

I&#39;ve been able to do this since the release of .NET 4 with [`CSharpCodeProvider.CompileAssemblyFromSource`][3] which I in fact use in an ASP.Net project written awhile ago that does exactly that - allows a user to type in code into a textbox, choose assemblies/namespaces to reference, and then execute and display the output from that code on-the-fly for live environment code testing on Windows Azure.

Is `CodeDom` part of / a precurser to Roslyn?  What&#39;s the special benefit of Roslyn over `CodeDom`?


  [1]: http://www.infoworld.com/d/application-development/microsofts-roslyn-reinventing-the-compiler-we-know-it-176671
  [2]: http://www.microsoft.com/download/en/details.aspx?id=27746
  [3]: http://msdn.microsoft.com/en-us/library/system.codedom.compiler.codedomprovider.compileassemblyfromsource.aspx

Microsoft Roslyn vs. CodeDom

Is it possible to draw a filled in triangle using XAML only (not a code behind solution)?

Triangle should be like on the image below to represent sort direction `Ascending/Descending` along with a sort button on a chart control:

![enter image description here][1]


**EDIT:** The solution, thanks to [SpeziFish][2]:

Ascending:

    &lt;Polygon Points=&quot;0,0 8,5, 0,10&quot; Stroke=&quot;Black&quot; Fill=&quot;Black&quot; /&gt;

Descending:
 

    &lt;Polygon Points=&quot;8,0 0,5, 8,10&quot; Stroke=&quot;Black&quot; Fill=&quot;Black&quot; /&gt;


  [1]: http://i.stack.imgur.com/nsqNv.png
  [2]: https://stackoverflow.com/users/444231/spezifish

Draw solid color triangle using XAML only

So I am learning MSIL right now to learn to debug my C# .NET applications.

I&#39;ve always wondered: **what is the purpose of the stack?** 

*Just to put my question in context:&lt;br/&gt;
Why is there a transfer from memory to stack or &quot;loading?&quot; 
On the other hand, why is there a transfer from stack to memory or &quot;storing&quot;?
**Why not just have them all placed in the memory?***

- Is it because it&#39;s faster?
- Is it because it&#39;s RAM based?
- For efficiency?

I&#39;m trying to grasp this to help me understand [CIL][1] codes much more deeply.

  [1]: http://en.wikipedia.org/wiki/Common_Intermediate_Language


What is the purpose of a stack? Why do we need it?

The code in question is below:  
 

    public static string ChangePersianDate(DateTime dateTime)
    {
        System.Globalization.GregorianCalendar PC = new System.Globalization.GregorianCalendar();
        PC.CalendarType = System.Globalization.GregorianCalendarTypes.USEnglish;
        return
        PC.GetYear(dateTime).ToString()
        + &quot;/&quot;
        + PC.GetMonth(dateTime).ToString()
        + &quot;/&quot;
        + PC.GetDayOfMonth(dateTime).ToString()
        + &quot;&quot;
        + PC.GetHour(dateTime).ToString()
        + &quot;:&quot;
        + PC.GetMinute(dateTime).ToString()
        + &quot;:&quot;
        + PC.GetSecond(dateTime).ToString()
        + &quot; &quot;
        ????????????????
    }

how can I get the AM/PM from the `dateTime` value?  



How do I get the AM/PM value from a DateTime?

All,

I am stuck again trying to get my data in a format that I need it in. I have a text field that looks like this.

&gt; &quot;deangelo 001 deangelo
&gt; 
&gt; local origin of name: italain
&gt; 
&gt; from the american name deangelo
&gt; 
&gt; meaning: of the angels
&gt; 
&gt; emotional spectrum • he is a fountain of joy for all.
&gt; 
&gt; personal integrity • his good name is his most precious asset.
&gt; personality • it’s hard to soar with eagles when you’re surrounded by
&gt; turkeys! relationships • starts slowly, but a relationship with
&gt; deangelo builds over time. travel &amp;amp; leisure • a trip of a lifetime
&gt; is in his future.
&gt; 
&gt; career &amp;amp; money • a gifted child, deangelo will need to be
&gt; challenged constantly.
&gt; 
&gt; life’s opportunities • joy and happiness await this blessed person.
&gt; 
&gt; deangelo’s lucky numbers: 12 • 38 • 18 • 34 • 29 • 16
&gt; 
&gt; &quot;

What would the best way be in Postgresql to remove the carriage returns and new lines? I&#39;ve tried several things and none of them want to behave.

    select regexp_replace(field, E&#39;\r\c&#39;, &#39;  &#39;, &#39;g&#39;) from mytable
        WHERE id = 5520805582
    
    SELECT regexp_replace(field, E&#39;[^\&amp;\/,;\*\:.\&gt;\&lt;[:space:]a-zA-Z0-9-]&#39;, &#39; &#39;)
        FROM mytable
        WHERE field~ E&#39;[^\&amp;\/,;\*\:.\&lt;\&gt;[:space:]a-zA-Z0-9-]&#39;
        AND id = 5520805582;

Thanks in advance,
Adam

How to remove carriage returns and new lines in Postgresql?

I need to return results for two different matches from a single file.
    
    grep &quot;string1&quot; my.file

correctly returns the single instance of string1 in my.file

    grep &quot;string2&quot; my.file

correctly returns the single instance of string2 in my.file

but

    grep &quot;string1|string2&quot; my.file

returns nothing

in regex test apps that syntax is correct, so why does it not work for grep in cygwin ?

How to use regex OR in grep in Cygwin?

How to check if variable contains valid UUID/GUID identifier?

I&#39;m currently interested only in validating types 1 and 4, but it should not be a limitation to your answers.

How to test valid UUID/GUID?

I&#39;ve seen Ruby and Perl programmers do some [complicated code challenges][1] entirely with regexes. The [lookahead and lookbehind][2] capabilities in Perl regexes make them more powerful than the regex implementations in most other languages. I was wondering how powerful they really are.

Is there an easy way to either prove or disprove that Perl regexes are [Turing complete][3]?


  [1]: https://codegolf.stackexchange.com/questions/3596/regex-validating-regex
  [2]: http://www.regular-expressions.info/lookaround.html
  [3]: https://stackoverflow.com/questions/7284/what-is-turing-complete

Are Perl regexes turing complete?

I have the following regular expression (regex) in my `urls.py` and I&#39;d like  to know what it means. Specifically the `(?P&lt;category_slug&gt;` portion of the regex.

```python
r&#39;^category/(?P&lt;category_slug&gt;[-\w]+)/$
```

Content Type	Original Author	Original Content on Stackoverflow
Question	Troy Hunt	View Question on Stackoverflow
Solution 1 - .Net	Bohemian	View Answer on Stackoverflow
Solution 2 - .Net	xanatos	View Answer on Stackoverflow

Regex for string not containing multiple specific words

.Net Problem Overview

.Net Solutions

Solution 1 - .Net

Solution 2 - .Net

jQuery: Clearing Form Inputs

String concatenation in Java - when to use +, StringBuilder and concat

Attributions