From: Todd Benson <caduceass@...>
Date: 2008-05-17T01:37:25+09:00
Subject: Re: newbie questions

On Fri, May 16, 2008 at 10:52 AM, Jason Lillywhite
<jason.lillywhite@gmail.com> wrote:
> I feel like we need a Forum called, "Ruby Newbie" for people like me. Is
> there one?
>
> I am hoping someone could help me with the following (probably) simple
> questions (my nested questions are surrounded by **):
>
> 1. Someone said to use the following code for getting a string and
> printing to the screen:
>
> puts "Where do you live?"
> STDOUT.flush
> city = gets.chomp
> puts "I live in " + city
>
> **why not just do this:**
>
> puts "Where do you live?"
> city = gets()
> puts "I live in " + city

or...

puts "Where do you live?"
puts "You live in " << gets

>
> ??
>
> regarding STDOUT: the comment was made - STDOUT is a global constant
> which is the actual standard output stream for the program.
>
> **but is it necessary?**
>
> A comment was made: flush flushes any buffered data within io to the
> underlying operating system (note that this is Ruby internal buffering
> only; the OS may buffer the data as well). The usage is not mandatory
> but recommended.
>
> **I still don't understand why flush is recommended. Is my omission
> going to create a problem?**
>
> **I understand chomp to remove record separators from the end, is there
> another reason besides?**
>
> 2. Is there a place I can go to learn more about regular expressions?

I've occasionally found www.regexp.info useful.

> 3. In IRB, Float::DIG => 15
> **question: This is because float displays to 15 decimals, right?
> **question: I see "::" all the time, but don't understand it. What does
> :: mean? Is it showing hierarchy?

It's the scope operator.  Page 330 of the Pickaxe, 2nd Ed.

> 4. In the code below:
>
> class NameIt
>  def initialize(name)
>    @name = name
>  end
>  def to_s
>    puts "My name is: #{@name}"
>  end

  def to_s
    "My name is: " << name
    # no puts
  end

> end
>
> n1 = NameIt.new("tom")
> n2 = NameIt.new("sally")
>
> n1.to_s
> n2.to_s

puts n1
puts n2

>
> **the last 4 lines seem very repetative. this is something I've wondered
> for a long time. Is there a way to compact the last 4 lines if you are
> trying to list a whole bunch of names at once using the method to_s?
>
> thank very much!
>
> Jason

Todd