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Bummer...Is there a way to accomplish a negative look back in JS?
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Bummer...Is there a way to accomplish a negative look back in JS?

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<a href="http://blog.stevenlevithan.com/archives/mimic-lookbehind-javascript" rel="ugc">http://blog.stevenlevithan.com/archives/mimic-lookbehind-javascript</a>
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http://blog.stevenlevithan.com/archives/mimic-lookbehind-javascript [http://blog.stevenlevithan.com/archives/mimic-lookbehind-javascript]

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Thanks for the quick response!
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Thanks for the question and the points.
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Doesn't /^((?!P\.?\s?O\.?\sBox).)+<wbr />$/i do he same thing?
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Doesn't /^((?!P\.?\s?O\.?\sBox).)+$/i do he same thing?

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It does...I'll report back if any of my test cases fail.
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It does...I'll report back if any of my test cases fail.

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<div class="content wysiwyg-content">
i am using a regex in Javascript and keep getting an error. &nbsp;I have used the same regex on several tester sites andthe parse works fine. &nbsp;I can't figure out hwy it isn't working my implementation.<br />
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Here is the code snippet:<br />
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&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;var re = /^((?&lt;!P\.?\s?O\.?\sBox).)<wbr />+(?&lt;!P\.?\<wbr />s?O\.?\sBo<wbr />x)$/i;<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;alert(&quot;??&quot;+re.Exec(documen<wbr />t.register<wbr />form.b_add<wbr />ress.value<wbr />));<br />
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It doesn't get to the alert before Firefox throws this error:<br />
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Error: invalid quantifier ?&lt;!P\.?\s?O\.?\sBox).)+(?&lt;<wbr />!P\.?\s?O\<wbr />.?\sBox)$<br />
Source File: ...<br />
Source Code:<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;var re = /^((?&lt;!P\.?\s?O\.?\sBox).)<wbr />+(?&lt;!P\.?\<wbr />s?O\.?\sBo<wbr />x)$/i;<br />
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Thoughts?<br />

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i am using a regex in Javascript and keep getting an error.  I have used the same regex on several tester sites andthe parse works fine.  I can't figure out hwy it isn't working my implementation.

Here is the code snippet:

	var re = /^((?<!P\.?\s?O\.?\sBox).)+(?<!P\.?\s?O\.?\sBox)$/i;
	alert("??"+re.Exec(document.registerform.b_address.value));

It doesn't get to the alert before Firefox throws this error:

Error: invalid quantifier ?<!P\.?\s?O\.?\sBox).)+(?<!P\.?\s?O\.?\sBox)$
Source File: ...
Source Code:
	var re = /^((?<!P\.?\s?O\.?\sBox).)+(?<!P\.?\s?O\.?\sBox)$/i;

Thoughts?


Javascript RegEx failing....

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.