Any reason why this code should not work - The Ruby Way, p270

Victor_Reyes · 8 May 2008 12:09

I lifted the following code from The Ruby way and tried to use it.
It does not output anything.
Do anyone knows why?

Thank you

Victor

···

##############################
# This code adds a count method to the Array class
# This code was lifted from:
# The Ruby Way
# Second Edition
# By: Hal Fulton
# Page: 270
##############################
class Array
       def count
            k=Hash.new(0)
            self.each{|x| k[x]+1 }
            k
       end
end

@aa = [

[123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789],

[123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789]
]

    @ga = [
            [0,0,0,0,1,9,0,4,0],
            [0,0,4,8,0,0,6,0,0],
            [7,5,0,0,0,0,0,0,2],
            [0,9,0,1,0,2,0,0,4],
            [0,0,0,0,0,3,0,0,0],
            [5,0,0,4,0,6,0,3,0],
            [8,0,0,0,0,0,0,7,3],
            [0,0,6,0,0,8,4,0,0],
            [0,1,0,2,9,0,0,0,0]
            ]

# Test the count method:

f = @ga[0].count
puts "f = #{f}" # The output here was: f =

f = @aa.count
puts "f = #{f}" # The output here was: f =

Jan_Svitok · 8 May 2008 12:22

I lifted the following code from The Ruby way and tried to use it.
It does not output anything.
Do anyone knows why?

Thank you

Victor

##############################
# This code adds a count method to the Array class
# This code was lifted from:
# The Ruby Way
# Second Edition
# By: Hal Fulton
# Page: 270
##############################
class Array
def count
k=Hash.new(0)

- self.each{|x| k+1 }
+ self.each{|x| k+=1 }

# notice the = sign, you have not stored the result anywhere.

···

On Thu, May 8, 2008 at 2:09 PM, Victor Reyes <victor.reyes@gmail.com> wrote:

            k
       end
end

    @aa = [

[123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789],

[123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789],

[123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789],

[123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789],

[123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789],

[123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789],

[123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789],

[123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789],

[123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789]
        ]

    @ga = [
            [0,0,0,0,1,9,0,4,0],
            [0,0,4,8,0,0,6,0,0],
            [7,5,0,0,0,0,0,0,2],
            [0,9,0,1,0,2,0,0,4],
            [0,0,0,0,0,3,0,0,0],
            [5,0,0,4,0,6,0,3,0],
            [8,0,0,0,0,0,0,7,3],
            [0,0,6,0,0,8,4,0,0],
            [0,1,0,2,9,0,0,0,0]
            ]

# Test the count method:

         f = @ga[0].count
         puts "f = #{f}" # The output here was: f =

         f = @aa.count
         puts "f = #{f}" # The output here was: f =

Rolando_Abarca · 8 May 2008 12:26

I think it should read:

def count
   k = Hash.new(0)
   self.each { |x| k += 1 }
   k
end

The problem is that inside the 'each' loop you're not asigning any value.
regards,

···

On May 8, 2008, at 8:09 AM, Victor Reyes wrote:

I lifted the following code from The Ruby way and tried to use it.
It does not output anything.
Do anyone knows why?

Thank you

Victor

##############################
# This code adds a count method to the Array class
# This code was lifted from:
# The Ruby Way
# Second Edition
# By: Hal Fulton
# Page: 270
##############################
class Array
      def count
           k=Hash.new(0)
           self.each{|x| k+1 }
           k
      end
end

--
Rolando Abarca M.

Jesus_Gabriel_y_Gala · 8 May 2008 12:28

I lifted the following code from The Ruby way and tried to use it.
It does not output anything.
Do anyone knows why?

Thank you

Victor

##############################
# This code adds a count method to the Array class
# This code was lifted from:
# The Ruby Way
# Second Edition
# By: Hal Fulton
# Page: 270
##############################
class Array
      def count
           k=Hash.new(0)
           self.each{|x| k+1 }

I think this line should be
self.each{|x| k += 1}

(notice the = sign, so the value gets assigned to the key).
Otherwise you are never adding entries to the hash

k
end
end

Hope this helps,

Jesus.

···

On Thu, May 8, 2008 at 2:09 PM, Victor Reyes <victor.reyes@gmail.com> wrote:

Victor_Reyes · 8 May 2008 12:33

Embarrassing!!!!!!!!! To say the least!
Even when I copy, I don't copy right!

Thank you Jano!

···

On Thu, May 8, 2008 at 8:22 AM, Jano Svitok <jan.svitok@gmail.com> wrote:

On Thu, May 8, 2008 at 2:09 PM, Victor Reyes <victor.reyes@gmail.com> > wrote:
> I lifted the following code from The Ruby way and tried to use it.
> It does not output anything.
> Do anyone knows why?
>
> Thank you
>
> Victor
>
> ##############################
> # This code adds a count method to the Array class
> # This code was lifted from:
> # The Ruby Way
> # Second Edition
> # By: Hal Fulton
> # Page: 270
> ##############################
> class Array
> def count
> k=Hash.new(0)

- self.each{|x| k+1 }
+ self.each{|x| k+=1 }

# notice the = sign, you have not stored the result anywhere.

> k
> end
> end
>
>
>
> @aa = [
>
>
[123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789],
>
>
[123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789],
>
>
[123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789],
>
>
[123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789],
>
>
[123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789],
>
>
[123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789],
>
>
[123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789],
>
>
[123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789],
>
>
[123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789]
> ]
>
> @ga = [
> [0,0,0,0,1,9,0,4,0],
> [0,0,4,8,0,0,6,0,0],
> [7,5,0,0,0,0,0,0,2],
> [0,9,0,1,0,2,0,0,4],
> [0,0,0,0,0,3,0,0,0],
> [5,0,0,4,0,6,0,3,0],
> [8,0,0,0,0,0,0,7,3],
> [0,0,6,0,0,8,4,0,0],
> [0,1,0,2,9,0,0,0,0]
> ]
>
>
> # Test the count method:
>
> f = @ga[0].count
> puts "f = #{f}" # The output here was: f =
>
> f = @aa.count
> puts "f = #{f}" # The output here was: f =
>

Victor_Reyes · 8 May 2008 12:43

Thank you Rolando. It was my silly typo!

···

On Thu, May 8, 2008 at 8:26 AM, Rolando Abarca <funkaster@gmail.com> wrote:

On May 8, 2008, at 8:09 AM, Victor Reyes wrote:

I lifted the following code from The Ruby way and tried to use it.

It does not output anything.
Do anyone knows why?

Thank you

Victor

##############################
# This code adds a count method to the Array class
# This code was lifted from:
# The Ruby Way
# Second Edition
# By: Hal Fulton
# Page: 270
##############################
class Array
     def count
          k=Hash.new(0)
          self.each{|x| k+1 }
          k
     end
end

I think it should read:

def count
k = Hash.new(0)
self.each { |x| k += 1 }
k
end

The problem is that inside the 'each' loop you're not asigning any value.
regards,
--
Rolando Abarca M.

Victor_Reyes · 8 May 2008 12:35

Yes, Jesus - Thank you!
It is, as I said earlier, embarrassing!

BTW Jesus, on what country are you located? I'm in Brooklyn New York, USA.

···

On Thu, May 8, 2008 at 8:33 AM, Victor Reyes <victor.reyes@gmail.com> wrote:

Embarrassing!!!!!!!!! To say the least!
Even when I copy, I don't copy right!

Thank you Jano!

On Thu, May 8, 2008 at 8:22 AM, Jano Svitok <jan.svitok@gmail.com> wrote:

On Thu, May 8, 2008 at 2:09 PM, Victor Reyes <victor.reyes@gmail.com> >> wrote:
> I lifted the following code from The Ruby way and tried to use it.
> It does not output anything.
> Do anyone knows why?
>
> Thank you
>
> Victor
>
> ##############################
> # This code adds a count method to the Array class
> # This code was lifted from:
> # The Ruby Way
> # Second Edition
> # By: Hal Fulton
> # Page: 270
> ##############################
> class Array
> def count
> k=Hash.new(0)

- self.each{|x| k+1 }
+ self.each{|x| k+=1 }

# notice the = sign, you have not stored the result anywhere.

> k
> end
> end
>
>
>
> @aa = [
>
>
[123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789],
>
>
[123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789],
>
>
[123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789],
>
>
[123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789],
>
>
[123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789],
>
>
[123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789],
>
>
[123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789],
>
>
[123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789],
>
>
[123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789,123456789]
> ]
>
> @ga = [
> [0,0,0,0,1,9,0,4,0],
> [0,0,4,8,0,0,6,0,0],
> [7,5,0,0,0,0,0,0,2],
> [0,9,0,1,0,2,0,0,4],
> [0,0,0,0,0,3,0,0,0],
> [5,0,0,4,0,6,0,3,0],
> [8,0,0,0,0,0,0,7,3],
> [0,0,6,0,0,8,4,0,0],
> [0,1,0,2,9,0,0,0,0]
> ]
>
>
> # Test the count method:
>
> f = @ga[0].count
> puts "f = #{f}" # The output here was: f =
>
> f = @aa.count
> puts "f = #{f}" # The output here was: f =
>

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Any reason why this code should not work - The Ruby Way, p270

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