asked on

use variable in regexp

So I have a working regular expression that does what I want. The problem is that I need to insert a variable into the regexp. The code is attached. How do I get the second code snippet to work.

WORKS
<script type="text/javascript">
  var re = /(\b)(glossary term)(?![^<]*>|[^<]*<\/a>)/g;
  var sourcestring = 'aglossary term <a href="page.aspx">glossary term</a> glossary term <test glossary term test> glossary term';
  var replacementpattern = '$1<a href="glossary.aspx#$2" title="def" class="glossary">$2</a>';
  var result = sourcestring.replace(re, replacementpattern);
  alert("result = " + result);
</script>
 
DOES NOT WORK
<script type="text/javascript">
  var word="glossary term";
  var re = new RegExp("(\b)("+word+")(?![^<]*>|[^<]*<\/a>)","g");
  var sourcestring = 'aglossary term <a href="page.aspx">glossary term</a> glossary term <test glossary term test> glossary term';
  var replacementpattern = '$1<a href="glossary.aspx#$2" title="def" class="glossary">$2</a>';
  var result = sourcestring.replace(re, replacementpattern);
  alert("result = " + result);
</script>

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hielo

Try:

var re = new RegExp("(\\b)("+word+")(?![^<]*>|[^<]*<\\/a>)","g");

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mattjp88

ASKER

no dice

hielo

What part is not working. Both seem to be alerting the same value

mattjp88

ASKER

in FF 3 it alerts 2 different values

<script type="text/javascript">
  var re = /(\b)(glossary term)(?![^<]*>|[^<]*<\/a>)/g;
  var sourcestring = 'aglossary term <a href="page.aspx">glossary term</a> glossary term <test glossary term test> glossary term';
  var replacementpattern = '$1<a href="glossary.aspx#$2" title="def" class="glossary">$2</a>';
  var result = sourcestring.replace(re, replacementpattern);
  alert("result = " + result);
</script>
 
<script type="text/javascript">
  var word="glossary term";
  var re = new RegExp("(\b)("+word+")(?![^<]*>|[^<]*<\/a>)","g");
  var sourcestring = 'aglossary term <a href="page.aspx">glossary term</a> glossary term <test glossary term test> glossary term';
  var replacementpattern = '$1<a href="glossary.aspx#$2" title="def" class="glossary">$2</a>';
  var result = sourcestring.replace(re, replacementpattern);
  alert("result = " + result);
</script>

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ASKER CERTIFIED SOLUTION

hielo

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mattjp88

ASKER

Don't know what I did before, but your code works. Thanks!!

hielo

You are welcome!