Each_with_index

Ruby
1

hello everybody! i’m working on a programm that has that peace of code:

def show_titles
file = File.read(“articles_file.txt”)
raw_articles = file.split("\n\n")
raw_articles.each do |elem|
title, *text = elem.split("\n")
@array_of_splits << Article.new(title, text.join(" "))
end
@array_of_splits.each_with_index do |elem, index|
puts “#{index}: #{elem.title}”

end

the next thing i wanna do is to let the user through gets pick the title
and then the whole article must show up in a console. For example:

  1. Title 1
  2. Title 2
  3. Title 3

Pick the title of the article
gets = 2

Title 2
text 2 text 2…

The question is how can i do that using each_with_index ? Thank u!

2

On Fri, Oct 8, 2010 at 10:41 AM, Pavel V. [email protected]
wrote:

puts “#{index}: #{elem.title}”
Pick the title of the article
gets = 2

Title 2
text 2 text 2…

The question is how can i do that using each_with_index ? Thank u!

You don’t need each_with_index for that. You have the list of articles
in @array_of_splits, so you just use [] to get the correct article:

choice = gets.to_i - 1 # the array starts at 0
@array_of_splits[choice] # returns the Article, show the fields you want

Jesus.

3

On Fri, Oct 8, 2010 at 10:41 AM, Pavel V. [email protected]
wrote:

puts “#{index}: #{elem.title}”
Pick the title of the article
gets = 2

Title 2
text 2 text 2…

The question is how can i do that using each_with_index ? Thank u!

You don’t. You just use Array#[], i.e. indexed access into the Array.

irb(main):005:0> a=%w{foo bar}
=> [“foo”, “bar”]
irb(main):006:0> a.each_with_index {|e,i| printf “%2d %p\n”,i,e}
0 “foo”
1 “bar”
=> [“foo”, “bar”]
irb(main):007:0> a[1]
=> “bar”

Kind regards

robert

4

You don’t need each_with_index for that. You have the list of articles
in @array_of_splits, so you just use [] to get the correct article:

choice = gets.to_i - 1 # the array starts at 0
@array_of_splits[choice] # returns the Article, show the fields you want

Jesus.

Yes, but it returns me #Article:0xb78c49a4, not a title and a text!

5

You don’t need each_with_index for that. You have the list of articles
in @array_of_splits, so you just use [] to get the correct article:

choice = gets.to_i - 1 # the array starts at 0
@array_of_splits[choice] # returns the Article, show the fields you want

Jesus.

Yes, but it returns me #Article:0xb78c49a4, not a title and a text!

The Article object should have a title and a text.
A way to get a title is :

choice = gets.to_i - 1 # the array starts at 0
article = @array_of_splits[choice] # returns the Article, show the
fields you want
title = article.title

In the similar way, a text can be acquired. But we don’t know a name
of an Article object’s method to obtain a text.
You should know the name of the method.

Regards,

6

irb(main):005:0> a=%w{foo bar}
=> [“foo”, “bar”]
irb(main):006:0> a.each_with_index {|e,i| printf “%2d %p\n”,i,e}
0 “foo”
1 “bar”
=> [“foo”, “bar”]
irb(main):007:0> a[1]
=> “bar”

Thanks

7

The Article object should have a title and a text.
A way to get a title is :

choice = gets.to_i - 1 # the array starts at 0
article = @array_of_splits[choice] # returns the Article, show the
fields you want
title = article.title

In the similar way, a text can be acquired. But we don’t know a name
of an Article object’s method to obtain a text.
You should know the name of the method.

Regards,

thanks, i made it up this way:

def show_titles
file = File.read(“articles_file.txt”)
raw_articles = file.split("\n\n")
raw_articles.each do |elem|
title, *text = elem.split("\n")
@array_of_splits << Article.new(title, text.join("\n")) # w\o the
whole text in one line
end
@array_of_splits.each_with_index do |elem, index|
puts “#{index}: #{elem.title}”
end
puts
puts “Pick the article u wanna see by entering the number of the
title”
choice = gets.to_i
puts
puts “Title: #{@array_of_splits[choice].title}”
puts “Text: #{@array_of_splits[choice].text}”
end