On Sun, Nov 13, 2011 at 6:01 PM, Praveer <[email protected]> wrote:
> Hello all,
>
> I am reading the book Ruby on Rails Tutorial : Learning by Example
>
> At the end of chapter 4 theres a question. I tried many time but nit
> succeeding in solving it.
>
> Can you all please help me in writing a solution for the same?
>
> Question is :
>
> Using Listing 4.9 as a guide, combine the split, shuffle, and join
> methods to write a function that shuffles the letters in a given
> string.
>
> Listing 4.9. Skeleton for a string shuffle function :
>
> >> def string_shuffle(s)
> >> s.split('').?.?
> >> end
> => nil
> >> string_shuffle("foobar")
>
Hi, to tackle such a question, I would use a combination of:
* irb (or pry)
* ruby documentation (e.g. http://www.ruby-doc.org/core/Array.html)
* use the .class and .inspect method intensively to study what type and
content
the result of each intermediate step is
So, in the session below, you see how I would build-up the result of your
excersize:
peterv@ASUS:~$ ruby -v
ruby 1.9.3p0 (2011-10-30 revision 33570) [i686-linux]
peterv@ASUS:~$ irb
001:0> s = "foobar"
=> "foobar"
002:0> s.class
=> String
003:0> s.inspect
=> "\"foobar\""
004:0> # now look up the documentation for String#split (
http://www.ruby-doc.org/core-1.9.3/String.html)
005:0* ^C
005:0> s_split = s.split('')
=> ["f", "o", "o", "b", "a", "r"]
006:0> # now look up the documentation for Array#shuffle
007:0* ^C
007:0> s_split_shuffle = s_split.shuffle
=> ["o", "o", "f", "r", "a", "b"]
008:0> s_split_shuffle.class
=> Array
009:0> # now look up the documentation for Array#join
010:0* ^C
010:0> result = s_split_shuffle.join
=> "oofrab"
011:0> result.class
=> String
012:0> # so the answer is s.split('').shuffle.join
013:0* ^C
HTH,
Peter
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