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Thanks, the REGEX is good, but I get an error if there is no match.<br />
<br />
For example, <br />
getInside2p('Hello World'); // should return ''<br />
<br />
but that returns an error.<br />
<br />

<pre><code class="code-1 nolinks" id="code-20-41501329-1"><span>alert(getInside2p('http://example.com/dir/(S(u53ouszaxo3dis55xhfm0l45))/page.aspx?xyz'));</span>
<span>alert(getInside2p('xyz((hello))123'));</span>
<span>alert(getInside2p('hello'));</span>
<span></span>
<span>function getInside2p(str) {</span>
<span> return(str.match(/\([^\)]*\((.*)\)[^\(]*\)/))[1];</span>
<span>}</span>
</code></pre>
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The <i>[1]</i> at the end of line 6 is likely causing the error. It is attempting to select the first value of an array that might be generated by the match statement. When there is no match, the match method will return a null value which is not an array, so the <i>[1]</i> designation throws an error. However, this match statement will never return an array, so the <i>[1]</i> designation is unnecessary. In order for the match statement to return an array, the global flag would have to be included in the expression.
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I realize that the problem is cause because of the [1] at the end, however if I don't put that at the end I don't get the desire results. &nbsp; Please test this, thanks. 
<pre><code class="code-1 nolinks" id="code-20-41502183-1"><span>alert(getInside2p('http://example.com/dir/(S(u53ouszaxo3dis55xhfm0l45))/page.aspx?xyz'));</span>
<span>alert(getInside2p('xyz((hello))123'));</span>
<span>alert(getInside2p('hello'));</span>
<span></span>
<span>function getInside2p(str) {</span>
<span> return(str.match(/\([^\)]*\((.*)\)[^\(]*\)/))[1];</span>
<span>}</span>
</code></pre>
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What are the desired results for your sample code? Are you wanting to limit the match to what is between the inside quotes only, or what is between the double or nested quotes?
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Here are the desired results:<br />
<br />
getInside2p('/dir/(S(u53ou<wbr />szaxo3dis5<wbr />5xhfm0l45)<wbr />)/page.asp<wbr />x?xyz'); // should return 'u53ouszaxo3dis55xhfm0l45'<wbr /><br />
getInside2p('xyz((hello))1<wbr />23'); // should return 'hello'<br />
getInside2p('Hello World'); // should return an empty result<br />
<br />
I want to limit the match to only what is inside two layers of parenthesis and if there is no match the the result should be empty.
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<div class="content wysiwyg-content">
Using JavaScript and Regular Expressions, how can I get the content inside a double set of parenthesis?<br />
<br />

<pre><code class="code-1 nolinks" id="code-10-28932193-1"><span>getInside2p('http://example.com/dir/(S(u53ouszaxo3dis55xhfm0l45))/page.aspx?xyz'); // should return 'u53ouszaxo3dis55xhfm0l45'</span>
<span>getInside2p('xyz((hello))123'); // should return 'hello'</span>
<span>getInside2p('Hello World'); // should return ''</span>
</code></pre>
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Using JavaScript and Regular Expressions, how can I get the content inside a double set of parenthesis?

(CODE)

JavaScript/REGEX: Inside a double set of parenthesis

jQuery (Core) is a cross-browser JavaScript library that provides abstractions for common client-side tasks such as Document Object Model (DOM) traversal, DOM manipulation, event handling, animation and Ajax. jQuery also provides a platform to create plugins that extend jQuery's capabilities beyond those already provided by the library.

jQuery

JavaScript is a dynamic, object-based language commonly used for client-side scripting in web browsers. Recently, server side JavaScript frameworks have also emerged. JavaScript runs on nearly every operating system and  in almost every mainstream web browser.

JavaScript

A regular expression ("regex") is a sequence of characters that define a search pattern, mainly for use in pattern matching with strings, or string matching, i.e. "find and replace"-like operations. Regular expression processors are found in several search engines, search and replace dialogs of several word processors and text editors, and in the command lines of text processing utilities, such as sed and AWK. Many programming languages provide regular expression capabilities, some built-in, for example Perl, JavaScript, Ruby, AWK, and Tcl, and others via a standard library, for example .NET languages, Java, Python and C++ (since C++11). Most other languages offer regular expressions via a library.