# Match with string instead of regexp fails **URL:** \ **Category:** ruby-talk\ **Created:** [11 October 2006 17:00 UTC](https://rubytalk.org/t/match-with-string-instead-of-regexp-fails/31798 "2006-10-11T17:00:15Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![Matt9](https://avatars.discourse-cdn.com/v4/letter/m/ea5d25/32.png) [@Matt9](https://rubytalk.org/u/Matt9)\ **Post date:** [11 October 2006 17:00 UTC](https://rubytalk.org/t/match-with-string-instead-of-regexp-fails/31798/1 "2006-10-11T17:00:15Z")
According to the 1.8.5 core API: str =~ obj =\> fixnum or nil Match. If obj is a Regexp, use it as a pattern to match against str. If obj is a String, look for it in str (similar to String#index). Returns the position the match starts, or nil if there is no match. So I expect "cat" =~ "a" #=\> 1 But: irb(main):013:0\> RUBY\_VERSION =\> "1.8.5" irb(main):014:0\> "cat" =~ "a" TypeError: type mismatch: String given         from (irb):14:in `=~'         from (irb):14 An undocumented change? Sorry if this has come up before, I did try to find out. Thx - m. > **···** > > from :0 > > -- > matt neuburg, phd = [matt@tidbits.com](mailto:matt@tidbits.com), [http://www.tidbits.com/matt/](http://www.tidbits.com/matt/) > Tiger - [http://www.takecontrolbooks.com/tiger-customizing.html](http://www.takecontrolbooks.com/tiger-customizing.html) > AppleScript - [http://www.amazon.com/gp/product/0596102119](http://www.amazon.com/gp/product/0596102119) > Read TidBITS! It's free and smart. [http://www.tidbits.com](http://www.tidbits.com) ---
**Author:** ![Jan\_Svitok](https://avatars.discourse-cdn.com/v4/letter/j/cab0a1/32.png) [@Jan\_Svitok](https://rubytalk.org/u/Jan_Svitok)\ **Post date:** [11 October 2006 19:06 UTC](https://rubytalk.org/t/match-with-string-instead-of-regexp-fails/31798/2 "2006-10-11T19:06:35Z")
In the CVS [1] there's a new documentation omitting the 'string' clause, so I suppose it's a documentation error. If you know a bit of C you can see for yourself. From the CVS history - the TypeError was added around 1.8.2, so it's there pretty long. The doc was fixed between 1.8.5-pre1 and 1.8.5-pre2. Form that it seems that the docs on ruby-doc are rather old, and not exactly 1.8.5 ones as they say... [1] [http://www.ruby-lang.org/cgi-bin/cvsweb.cgi/ruby/string.c?rev=1.182.2.53;content-type=text%2Fplain](http://www.ruby-lang.org/cgi-bin/cvsweb.cgi/ruby/string.c?rev=1.182.2.53;content-type=text%2Fplain) > **···** > > On 10/11/06, matt neuburg \ wrote: > > > According to the 1.8.5 core API: > > > > str =~ obj =\> fixnum or nil > > > > Match. If obj is a Regexp, use it as a pattern to match against str. If > > obj is a String, look for it in str (similar to String#index). Returns > > the position the match starts, or nil if there is no match. > > > > So I expect "cat" =~ "a" #=\> 1 > > > > But: > > > > irb(main):013:0\> RUBY\_VERSION > > =\> "1.8.5" > > irb(main):014:0\> "cat" =~ "a" > > TypeError: type mismatch: String given > >         from (irb):14:in `=~' > >         from (irb):14 > >         from :0 > > > > An undocumented change? Sorry if this has come up before, I did try to > > find out. Thx - m. ---
**Author:** ![Matt9](https://avatars.discourse-cdn.com/v4/letter/m/ea5d25/32.png) [@Matt9](https://rubytalk.org/u/Matt9)\ **Post date:** [11 October 2006 20:40 UTC](https://rubytalk.org/t/match-with-string-instead-of-regexp-fails/31798/3 "2006-10-11T20:40:15Z")
Excellent, thanks. m. > **···** > > Jan Svitok \ wrote: > > > On 10/11/06, matt neuburg \ wrote: > > \> According to the 1.8.5 core API: > > \> > > \> str =~ obj =\> fixnum or nil > > \> > > \> Match. If obj is a Regexp, use it as a pattern to match against str. If > > \> obj is a String, look for it in str (similar to String#index). Returns > > \> the position the match starts, or nil if there is no match. > > \> > > \> So I expect "cat" =~ "a" #=\> 1 > > \> > > \> But: > > \> > > \> irb(main):013:0\> RUBY\_VERSION > > \> =\> "1.8.5" > > \> irb(main):014:0\> "cat" =~ "a" > > \> TypeError: type mismatch: String given > > \> from (irb):14:in `=~' > > \> from (irb):14 > > \> from :0 > > \> > > \> An undocumented change? Sorry if this has come up before, I did try to > > \> find out. Thx - m. > > > > In the CVS [1] there's a new documentation omitting the 'string' > > clause, so I suppose it's a documentation error. > > > > If you know a bit of C you can see for yourself. > > > > From the CVS history - the TypeError was added around 1.8.2, so it's > > there pretty long. > > > > The doc was fixed between 1.8.5-pre1 and 1.8.5-pre2. Form that it > > seems that the docs on ruby-doc are rather old, and not exactly 1.8.5 > > ones as they say... > > > > [1] [http://www.ruby-lang.org/cgi-bin/cvsweb.cgi/ruby/string.c?rev=1.182.2.53](http://www.ruby-lang.org/cgi-bin/cvsweb.cgi/ruby/string.c?rev=1.182.2.53); > > content-type=text%2Fplain > > -- > matt neuburg, phd = matt@tidbits.com, [Matt Neuburg’s Home Page](http://www.tidbits.com/matt/) > Tiger - [http://www.takecontrolbooks.com/tiger-customizing.html](http://www.takecontrolbooks.com/tiger-customizing.html) > AppleScript - [http://www.amazon.com/gp/product/0596102119](http://www.amazon.com/gp/product/0596102119) > Read TidBITS! It's free and smart. [http://www.tidbits.com](http://www.tidbits.com)