From: matt@... (matt neuburg)
Date: 2009-06-06T02:05:09+09:00
Subject: Re: Test array and assign result to variable

Adrian Arlechin <adrian.cinta@gmail.com> wrote:

> I have this example:
> class Array
>   def find
>     for i in 0...size
>       value = self[i]
>       return value if yield(value)
>     end
>     return nil
>   end
> end
> x = [1, 3, 5, 7, 9]
> x.find {|v| v*v > 30 }
> It says that return 7 - the first value wich match the condition
> I run it in NetBeans but don't see the output

Because you didn't ask for any output. It would suffice to change the
last line from

x.find {|v| v*v > 30 }

to

puts x.find {|v| v*v > 30 }

> I tried this:
> x.find {|v|
>   if  v*v > 30
>     puts v
>   end }  but now prints the both values that match the condition: 7, 9
> So the problem is how can I see only the first match, and most important
> how can I extract this value to a variable to use it somewhere else.
> Because in general I want to test an array for a condition, and then use
> the results

It's good that you're trying to "roll your own" on this, but still,
Array#find already exists and does exactly what you're looking for.

m.


-- 
matt neuburg, phd = matt@tidbits.com, http://www.tidbits.com/matt/
Leopard - http://www.takecontrolbooks.com/leopard-customizing.html
AppleScript - http://www.amazon.com/gp/product/0596102119
Read TidBITS! It's free and smart. http://www.tidbits.com