RegEx Help

[Balance]

I need a little of RegEx help based on the following:

When there is a price associated with an element and an underscore is present.  The text that appears from the underscore to the price should be suppressed. For example:

The following string:

Cash Back_Requires Redemption _$5 for 12 Months Cl  $0.00

Would be translated to:
Cash Back $0.00

TIA

[Owainnorth]

Don't have my regex tester to hand, but you could always just use list functions:

<cfset str = "Cash Back_Requires Redemption _$5 for 12 Months Cl  $0.00" />

<cfoutput>#listFirst(str, '_')# #listLast(str, '$')#</cfoutput>

[Balance]

@Owain - Your suggestion kind of works, but the dollar sign is removed from 0.00 (and it shouldn't). Here's my version which, so far, seems to work:

<cfsavecontent variable="myString">

Cash Back_Requires Redemption _$5 for 12 Months Cl  $0.00

</cfsavecontent>

<cfset myString = listDeleteAt(myString,2,"_")>

<cfset myString = replace(myString,"_"," ","all")>

<cfset myString = listDeleteAt(myString,2,"$")>

<p><cfoutput>#myString#</cfoutput></p>

[Owainnorth]

@Owain - Your suggestion kind of works, but the dollar sign is removed from 0.00 (and it shouldn't).

You could always just put the dollar sign back in?

<cfsavecontent variable="myString">

Cash Back_Requires Redemption _$5 for 12 Months Cl  $0.00

</cfsavecontent>

Be careful using cfsavecontent for creating a simple string, it will've included a newline at the beginning and end of the string, which may or may not cause you issues in different circumstances. I'd use a simple cfset.

[Adam Cameron.]

When there is a price associated with an element and an underscore is present.  The text that appears from the underscore to the price should be suppressed. For example:

The following string:

Cash Back_Requires Redemption _$5 for 12 Months Cl  $0.00

Would be translated to:
Cash Back $0.00

If I understand your requirement correctly, this should do it:

^([^_]*?)_.*?(\$[^$]+?)$

I have to concede I didn't test all edge cases, but it seems to work.

--

Adam

[Balance]

@Adam,

Your RegEx seems to remove all characters.

Here's my CF code that verifies this:

<cfsavecontent variable="myString">

Cash Back_Requires Redemption _$5 for 12 Months Cl  $0.00

</cfsavecontent>

<cfset myString = REReplaceNoCase(myString,"^([^_]*?)_.*?(\$[^$]+?)$","","all")>

<p>len(myString) = <cfoutput>#len(myString)#</cfoutput></p> <!--- this returns 1, which is just an empty space --->

Here's my version, which so far, seems to work:

<cfset myString = listDeleteAt(myString,2,"_")>

<cfset myString = replace(myString,"_"," ","all")>

<cfset myString = listDeleteAt(myString,2,"$")>

[Adam Cameron. · Accepted solution]

Your RegEx seems to remove all characters.

[...]

<cfset myString = REReplaceNoCase(myString,"^([^_]*?)_.*?(\$[^$]+?)$","","all")>

Well it would do... you're replacing the match with nothing!

You need to replace it with the two captured subexpressions, eg:

s = reReplace(s, "^([^_]*?)_.*?(\$[^$]+?)$", "\1 \2", "ONE");

Sorry, I thought (well... I dunno how much I was thinking, to be honest 😉 you just needed help with the regex, not with how to use it.  Hence just posting the regex.

--

Adam

[Balance]

@Adam

Thanks for the updated code, that seems to have done the trick!

Do you use any resources or anything to build these ugly expressions? Books, websites, etc.

[Adam Cameron.]

Do you use any resources or anything to build these ugly expressions? Books, websites, etc.

Just the CF docs, really:

http://help.adobe.com/en_US/ColdFusion/9.0/Developing/WSc3ff6d0ea77859461172e0811cbec0a38f-7ffb.html

And a lot of practise & experimentation.  Years ago, I made a point of trying to use them whenever I thought there might be good grounds to, so forced myself to practise.  After a while it becomes easier to read & write them.

I'm still learning though.  I need to sit down and really think about how look-aheads and stuff work, when I need to use one.

I use Regex Coach for testing them:

http://weitz.de/regex-coach/

It's not 100% compatible with the regex library that CF uses, but it's close enough for most purposes.

--

Adam