# Search in string with regular expression **URL:** \ **Category:** Ruby\ **Created:** [July 15, 2009, 11:20am UTC](https://www.ruby-forum.com/t/search-in-string-with-regular-expression/172133 "2009-07-15T11:20:50Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![mickesommar](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/c5a1d2/32.png) [@mickesommar](https://www.ruby-forum.com/u/mickesommar)\ **Post date:** [July 15, 2009, 11:20am UTC](https://www.ruby-forum.com/t/search-in-string-with-regular-expression/172133/1 "2009-07-15T11:20:50Z")
Hi all I’m trying to build a new string from a existing one. The original string is: my frog name is froggy I will pull out only: frog froggy ## I have tried the following: str1 = ‘my frog name is froggy’ str2 = str1[/frog|froggy/] puts str2 * * * This will print only the string: frog ## I can get the information with this code: str1 = ‘my frog name is froggy’ str2 = str1[/frog] + " " + str1[/froggy/] ## puts str2 This will print the string: frog froggy But i think it is possible to solve this in a better way, Any suggestions ? // Micke ---
**Author:** ![mickesommar](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/c5a1d2/32.png) [@mickesommar](https://www.ruby-forum.com/u/mickesommar)\ **Post date:** [July 15, 2009, 11:58am UTC](https://www.ruby-forum.com/t/search-in-string-with-regular-expression/172133/2 "2009-07-15T11:58:45Z")
Micke M. wrote: > Hi all > > I’m trying to build a new string from a existing one. > > The original string is: my frog name is froggy > I will pull out only: frog froggy C:\Users\Alex\>irb irb(main):001:0\> str1 = ‘my frog name is froggy’ =\> “my frog name is froggy” irb(main):002:0\> str2=str1.scan( /froggy|frog/ ) =\> [“frog”, “froggy”] irb(main):003:0\> str3=str1.scan( /frog|froggy/ ) =\> [“frog”, “frog”] irb(main):004:0\> Li ---
**Author:** ![mickesommar](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/c5a1d2/32.png) [@mickesommar](https://www.ruby-forum.com/u/mickesommar)\ **Post date:** [July 15, 2009, 12:09pm UTC](https://www.ruby-forum.com/t/search-in-string-with-regular-expression/172133/3 "2009-07-15T12:09:02Z")
On 7/15/09, Micke M. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > str1 = ‘my frog name is froggy’ > str2 = str1[/frog|froggy/] > Maybe > str2 = str1.scan( /\bfrog\w\*\B/ ).join(" “) > that is if you want to match frog at the start of words only (\b) and > assure charcters of your choice up to the end of the word? As \w might > be a little bit too permissive, in 1.9 you might prefer > str2 = str1.scan( /\bfrog[[:alpha:]]\*\B/ ).join(” ") > and all those nice variations 😉 HTH Robert > ## str1 = ‘my frog name is froggy’ // Micke > > Posted via [http://www.ruby-forum.com/](http://www.ruby-forum.com/). – Toutes les grandes personnes ont d’abord été des enfants, mais peu d’entre elles s’en souviennent. All adults have been children first, but not many remember. [Antoine de Saint-Exupéry] ---
**Author:** ![mickesommar](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/c5a1d2/32.png) [@mickesommar](https://www.ruby-forum.com/u/mickesommar)\ **Post date:** [July 15, 2009, 12:48pm UTC](https://www.ruby-forum.com/t/search-in-string-with-regular-expression/172133/4 "2009-07-15T12:48:47Z")
> Or maybe, 🙂 str2 = str1.scan( /\bfrog\w\*\b/ ).join(" ") Harry ---
**Author:** ![mickesommar](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/c5a1d2/32.png) [@mickesommar](https://www.ruby-forum.com/u/mickesommar)\ **Post date:** [July 15, 2009, 3:06pm UTC](https://www.ruby-forum.com/t/search-in-string-with-regular-expression/172133/5 "2009-07-15T15:06:39Z")
On 7/15/09, Robert D. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > > > Robert > > > > Or maybe, 🙂 > > > > str2 = str1.scan( /\bfrog\w\*\b/ ).join(" ") > > No it was not a typo, I thought that \B was matching at the end of the > > word, I did not test with a frog at the end. > > I stand corrected \B does not have a special meaning and \b is just a > > word boundary. > > I mean \B is not a word boundary and \b is a word boundary and I > > wonder WHAT I did test??? > > Sorry > > R. ---
**Author:** ![mickesommar](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/c5a1d2/32.png) [@mickesommar](https://www.ruby-forum.com/u/mickesommar)\ **Post date:** [July 15, 2009, 3:04pm UTC](https://www.ruby-forum.com/t/search-in-string-with-regular-expression/172133/6 "2009-07-15T15:04:53Z")
On 7/15/09, Harry K. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > > > > Or maybe, 🙂 > > str2 = str1.scan( /\bfrog\w\*\b/ ).join(" ") > No it was not a typo, I thought that \B was matching at the end of the > word, I did not test with a frog at the end. > I stand corrected \B does not have a special meaning and \b is just a > word boundary. Thx Robert > A Look into Japanese Ruby List in English > [Kakueki.com is for sale | HugeDomains](http://www.kakueki.com/ruby/list.html) – Toutes les grandes personnes ont d’abord été des enfants, mais peu d’entre elles s’en souviennent. All adults have been children first, but not many remember. [Antoine de Saint-Exupéry] ---
**Author:** ![mickesommar](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/c5a1d2/32.png) [@mickesommar](https://www.ruby-forum.com/u/mickesommar)\ **Post date:** [July 15, 2009, 3:08pm UTC](https://www.ruby-forum.com/t/search-in-string-with-regular-expression/172133/7 "2009-07-15T15:08:24Z")
Hi – On Wed, 15 Jul 2009, Robert D. wrote: > > > Robert > > > > Or maybe, 🙂 > > > > str2 = str1.scan( /\bfrog\w\*\b/ ).join(" ") > > No it was not a typo, I thought that \B was matching at the end of the > > word, I did not test with a frog at the end. > > I stand corrected \B does not have a special meaning and \b is just a > > word boundary. \B is the opposite of \b, i.e., “not at a word boundary”. So: > > /\B./.match(“word”)[0] > > =\> “o” David