# Small improvements ideas? **URL:** \ **Category:** Ruby\ **Created:** [September 8, 2010, 1:41pm UTC](https://www.ruby-forum.com/t/small-improvements-ideas/194643 "2010-09-08T13:41:42Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![christophe1](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/b3f665/32.png) [@christophe1](https://www.ruby-forum.com/u/christophe1)\ **Post date:** [September 8, 2010, 1:41pm UTC](https://www.ruby-forum.com/t/small-improvements-ideas/194643/1 "2010-09-08T13:41:42Z")
Hello, I would like to know how to shorten these two lines 1. doit() if my\_string && my\_string.downcase == ‘hello’ 2. doit() if one\_var && (my\_string =~ /this\_regexp/) == nil Case 1) is a way to check for my\_string beeing nil (would break on downcase call). But it’s verbose, nothing better ?? Case 2) I want doit beeing call if regexp don’t match. would I use ! (my\_string =~ /this\_regexp/) but I don’t like using ! because it’s not very readable and I can’t use not keyword in this case Thanks ---
**Author:** ![christophe1](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/b3f665/32.png) [@christophe1](https://www.ruby-forum.com/u/christophe1)\ **Post date:** [September 8, 2010, 2:06pm UTC](https://www.ruby-forum.com/t/small-improvements-ideas/194643/2 "2010-09-08T14:06:53Z")
On Wed, Sep 8, 2010 at 5:08 PM, Chris [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Hello, I would like to know how to shorten these two lines > > 1. doit() if my\_string && my\_string.downcase == ‘hello’ > 2. doit() if one\_var && (my\_string =~ /this\_regexp/) == nil > > Case 1) is a way to check for my\_string beeing nil (would break on > downcase call). But it’s verbose, nothing better ?? 1. check out the andand library [[http://andand.rubyforge.org/](http://andand.rubyforge.org/)] doit() if my\_string.andand.downcase == “hello” > Case 2) I want doit beeing call if regexp don’t match. would I use ! > (my\_string =~ /this\_regexp/) but I don’t like using ! because it’s not > very readable and I can’t use not keyword in this case mystring !~ /this\_regexp/ martin ---
**Author:** ![christophe1](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/b3f665/32.png) [@christophe1](https://www.ruby-forum.com/u/christophe1)\ **Post date:** [September 8, 2010, 2:09pm UTC](https://www.ruby-forum.com/t/small-improvements-ideas/194643/3 "2010-09-08T14:09:13Z")
On Wednesday 08 September 2010, Chris wrote: > |Hello, I would like to know how to shorten these two lines > | > |1) doit() if my\_string && my\_string.downcase == ‘hello’ > |2) doit() if one\_var && (my\_string =~ /this\_regexp/) == nil > | > |Case 1) is a way to check for my\_string beeing nil (would break on > |downcase call). But it’s verbose, nothing better ?? > You can do if (my\_string || ‘’).downcase == ‘hello’ This way, if my\_string is nil, the parentheses will evaluate to ‘’ which is a string and will always be different from ‘hello’ > |Case 2) I want doit beeing call if regexp don’t match. would I use ! > |(my\_string =~ /this\_regexp/) but I don’t like using ! because it’s not > |very readable and I can’t use not keyword in this case I think you can: if one\_var && (not(my\_string =~ /this\_regexp/)) > |Thanks I hope this helps Stefano ---
**Author:** ![christophe1](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/b3f665/32.png) [@christophe1](https://www.ruby-forum.com/u/christophe1)\ **Post date:** [September 8, 2010, 2:25pm UTC](https://www.ruby-forum.com/t/small-improvements-ideas/194643/4 "2010-09-08T14:25:22Z")
Christophe G. wrote: > Hello, I would like to know how to shorten these two lines > > 1. doit() if my\_string && my\_string.downcase == ‘hello’ doit if /\Ahello\z/i =~ my\_string > 1. doit() if one\_var && (my\_string =~ /this\_regexp/) == nil > Case 2) I want doit beeing call if regexp don’t match. would I use ! > (my\_string =~ /this\_regexp/) but I don’t like using ! because it’s not > very readable and I can’t use not keyword in this case I’m not sure what “one\_var” is. If you meant “my\_string”, then note that you can use !~ as the inverse of =~ doit if /this\_regexp/ !~ my\_string or simply: doit unless /this\_regexp/ =~ my\_string ---
**Author:** ![christophe1](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/b3f665/32.png) [@christophe1](https://www.ruby-forum.com/u/christophe1)\ **Post date:** [September 8, 2010, 2:31pm UTC](https://www.ruby-forum.com/t/small-improvements-ideas/194643/5 "2010-09-08T14:31:28Z")
On Wed, Sep 8, 2010 at 5:50 PM, Robert K. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > On Wed, Sep 8, 2010 at 1:38 PM, Chris [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > > > Hello, I would like to know how to shorten these two lines > > > > 1. doit() if my\_string && my\_string.downcase == ‘hello’ > > doit if /\Ahello\z/i =~ my\_string ruby-1.9.2-p0 \> /hello/ =~ nil =\> nil wow, learnt something today! martin ---
**Author:** ![christophe1](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/b3f665/32.png) [@christophe1](https://www.ruby-forum.com/u/christophe1)\ **Post date:** [September 8, 2010, 2:24pm UTC](https://www.ruby-forum.com/t/small-improvements-ideas/194643/6 "2010-09-08T14:24:27Z")
On Wed, Sep 8, 2010 at 1:38 PM, Chris [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Hello, I would like to know how to shorten these two lines > > 1. doit() if my\_string && my\_string.downcase == ‘hello’ doit if /\Ahello\z/i =~ my\_string > 1. doit() if one\_var && (my\_string =~ /this\_regexp/) == nil doit if one\_var && /rx/ !~ my\_string > Case 1) is a way to check for my\_string beeing nil (would break on > downcase call). But it’s verbose, nothing better ?? > > Case 2) I want doit beeing call if regexp don’t match. would I use ! > (my\_string =~ /this\_regexp/) but I don’t like using ! because it’s not > very readable and I can’t use not keyword in this case Kind regards robert ---
**Author:** ![christophe1](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/b3f665/32.png) [@christophe1](https://www.ruby-forum.com/u/christophe1)\ **Post date:** [September 9, 2010, 8:15am UTC](https://www.ruby-forum.com/t/small-improvements-ideas/194643/7 "2010-09-09T08:15:49Z")
Thanks for your replies, I was totally unware of !~ !!!