From: Nag Raj <raju.srirangam@...>
Date: 2009-12-04T00:47:29+09:00
Subject: Re: Increment outerloop value in innerloop in each do Syntax

Florian Gilcher wrote:
> On Dec 2, 2009, at 9:28 PM, Nag Raj wrote:
> 
>>         {
>>            printf("%d - its J value\n",j);
>>            i++;
>>         }
>>      }
>>      printf("%d - its I value\n",i);
>>   }
> 
> Wow, is there any use case for this pattern?
> 
>> end
> Be aware that i or j are in no way the same as i and j in
> your C program. Here, you iterate over the set of natural
> numbers from 0..9 and 0..5, binding i and j to those values
> for every step of the iteration. So i and j are not controlling
> your iteration - each does.
> So any change to i and j will be lost at the end of the do-block.
> 
> But, with a bit of trickery, you can achieve this:
> 
>    (0..9).each do |i|
>      if j = (0..5).find{ |j| i==j }
>        puts "#{j} J Value"
>      else
>        puts "#{i} I Value"
>      end
>    end
> 
> #find finds the first element of the range that satisfies
> the condition given in the block. If there is none, it returns
> nil, which is not true in a boolean sense. As the statement in
> the condition can be any ruby expression (because the always return
> a value, there is no void), we can immediately assign that to j.
> 
> As j has a true value (everything but nil and false) if the find
> condition matches, the first branch of the if is used. Otherwise,
> j is nil and i is printed.
> 
> Again: you iterate over a set, this is no counting loop. This might
> take a bit to get used to, but in the end, you can use such nice
> things as #find, #map, #inject on it. Learn them, they are a rubyists
> mightiest tools.
> 
> Have a lot of fun.
> 
> Regards,
> Florian Gilcher


Hi All,

Thank you very much Michael and Florian for your help. I am sorry John 
if I made something wrong. I tried with continue, break and next. 
Nothing worked out for me. Unluckily I have to insert some code 
according to this pattern. Because remaining file maintained this format 
so I have to. At last after some manipulation, I got the below code 
which works similar to the above codes given by Michael and Florian. 
Once again thank you very much for the help.

myval = true
(0..9).each do |i|
   (0..5).each do |j|
      if(i==j)
         puts "#{j} its J value"
         myval = false
      end
   end
   if(myval)
      puts "#{i} its I value"
   end
   myval = true
end

Regards,
Nag
-- 
Posted via http://www.ruby-forum.com/.