# Extracting matching string, else null
**URL:** https://community.mp3tag.de/t/extracting-matching-string-else-null/8738
**Category:** Support
**Created:** [August 8, 2009, 12:15pm UTC](https://community.mp3tag.de/t/extracting-matching-string-else-null/8738 "2009-08-08T12:15:07Z")
**Posts on this page:** 12
**Page:** 1
### Author:  [@chrisjj](https://community.mp3tag.de/u/chrisjj)
#### Post date: [August 8, 2009, 12:15pm UTC](https://community.mp3tag.de/t/extracting-matching-string-else-null/8738/1 "2009-08-08T12:15:07Z")
What''s the most concise script expression that will return the match of regexp EEE in string SSS, else if there is no match, null?
Like **$if($regexpmatch(SSS,EEE),$regexp(SSS,EEE) , )** if $regexpmatch was available 🙂
Thanks.
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### Author:  [@DetlevD](https://community.mp3tag.de/u/DetlevD)
#### Post date: [August 8, 2009, 3:29pm UTC](https://community.mp3tag.de/t/extracting-matching-string-else-null/8738/2 "2009-08-08T15:29:13Z")
If match then result is 1, if no match then result is 0.
Example:
$if($neql('20090808',$regexp('20090808','8',)),1,0)
DD.20090808.1929.CEST
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### Author:  [@chrisjj](https://community.mp3tag.de/u/chrisjj)
#### Post date: [August 9, 2009, 12:26pm UTC](https://community.mp3tag.de/t/extracting-matching-string-else-null/8738/3 "2009-08-09T12:26:36Z")
> $if($neql('20090808',$regexp('20090808','8',)),1,0)
To meet the requirement that way, it seems we would need
$if($neql(SSS,$regexp(SSS,EEE,RRR)),$regexp(SSS,EEE,RRR),)
Is there a solution that requires less duplication?
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### Author:  [@DetlevD](https://community.mp3tag.de/u/DetlevD)
#### Post date: [August 9, 2009, 12:56pm UTC](https://community.mp3tag.de/t/extracting-matching-string-else-null/8738/4 "2009-08-09T12:56:05Z")
> [@chrisjj](#):
>
> ... it seems we would need
> $if($neql(SSS,$regexp(SSS,EEE,RRR)),$regexp(SSS,EEE,RRR),) ...
I think it should be read ...
**$if($neql(SSS,$regexp(SSS,EEE,)),$regexp(SSS,EEE,RRR),)**
DD.20090809.1655.CEST
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### Author:  [@chrisjj](https://community.mp3tag.de/u/chrisjj)
#### Post date: [August 9, 2009, 1:12pm UTC](https://community.mp3tag.de/t/extracting-matching-string-else-null/8738/5 "2009-08-09T13:12:36Z")
> I think it should be read ...
> **$if($neql(SSS,$regexp(SSS,EEE,)),$regexp(SSS,EEE,RRR),)**
Aha, yes - thanks.
So is this "the most concise script expression", to do think? I would really like one without duplication, since SSS and sometimes EEE can be long expressions.
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### Author:  [@chrisjj](https://community.mp3tag.de/u/chrisjj)
#### Post date: [August 9, 2009, 1:15pm UTC](https://community.mp3tag.de/t/extracting-matching-string-else-null/8738/6 "2009-08-09T13:15:44Z")
> [@DetlevD](#):
>
> If match then result is 1, if no match then result is 0.
> Example:
> $if($neql('20090808',$regexp('20090808','8',)),1,0)
Note fails in the case
$if($neql(,$regexp(,'^$',)),1,0)
(returns 0) though this is not a problem to my application.
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### Author:  [@DetlevD](https://community.mp3tag.de/u/DetlevD)
#### Post date: [August 9, 2009, 1:17pm UTC](https://community.mp3tag.de/t/extracting-matching-string-else-null/8738/7 "2009-08-09T13:17:13Z")
... and this can also happen ...
**$if($neql(SSS,$regexp(SSS,EEE,)),$regexp(SSS,EEE,RRR),SSS)**
... if someone wants to leave the original string untouched.
DD.20090809.1716.CEST
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### Author:  [@chrisjj](https://community.mp3tag.de/u/chrisjj)
#### Post date: [August 9, 2009, 3:42pm UTC](https://community.mp3tag.de/t/extracting-matching-string-else-null/8738/8 "2009-08-09T15:42:36Z")
> [@DetlevD](#):
>
> ... and this can also happen ...
> **$if($neql(SSS,$regexp(SSS,EEE,)),$regexp(SSS,EEE,RRR),SSS)**
> ... if someone wants to leave the original string untouched.
Surely $regexp itself is sufficient for that, since it leaves the original string untouched if no match.
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### Author:  [@DetlevD](https://community.mp3tag.de/u/DetlevD)
#### Post date: [August 9, 2009, 4:28pm UTC](https://community.mp3tag.de/t/extracting-matching-string-else-null/8738/9 "2009-08-09T16:28:38Z")
> [@chrisjj](#):
>
> Surely $regexp itself is sufficient for that, since it leaves the original string untouched if no match.
The second regexp replace can only work when the first regexp catches a match, otherwise the if clause will return nothing, which would be able to distort the current field value, if this function starts from/with the value of the current field.
DD.20090809.2028.CEST
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### Author:  [@chrisjj](https://community.mp3tag.de/u/chrisjj)
#### Post date: [August 9, 2009, 6:44pm UTC](https://community.mp3tag.de/t/extracting-matching-string-else-null/8738/10 "2009-08-09T18:44:51Z")
> [@DetlevD](#):
>
> The second regexp replace can only work when the first regexp catches a match, otherwise the if clause will return nothing, which would be able to distort the current field value, if this function starts from/with the value of the current field.
Agreed, but what I am saying is surely
$if($neql(SSS,$regexp(SSS,EEE,)),$regexp(SSS,EEE,RRR),SSS)
and
$regexp(SSS,EEE,RRR)
give the same result.
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### Author:  [@DetlevD](https://community.mp3tag.de/u/DetlevD)
#### Post date: [August 10, 2009, 1:38am UTC](https://community.mp3tag.de/t/extracting-matching-string-else-null/8738/11 "2009-08-10T01:38:07Z")
> [@chrisjj](#):
>
> Agreed, but what I am saying is surely
> $if($neql(SSS,$regexp(SSS,EEE,)),$regexp(SSS,EEE,RRR),SSS) and $regexp(SSS,EEE,RRR) give the same result.
Yes, in this case there is no need to detect possible matching previously.
DD.20090910.0538.CEST
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### Author:  [@system](https://community.mp3tag.de/u/system)
#### Post date: [February 9, 2026, 12:21pm UTC](https://community.mp3tag.de/t/extracting-matching-string-else-null/8738/12 "2026-02-09T12:21:42Z")