From: Stefan Mahlitz <stefan@...>
Date: 2006-06-17T05:46:06+09:00
Subject: Re: undefined method (noMethodError)

Parv G wrote:
> Stefan Mahlitz wrote:
> 
>> If you want the object to change its content you will have to define
>> instance variables.
>>
>> def initialize
>>   @col = 'A'
>> end
>>
>> In nextcell you have to change all occurences of 'col' to '@col'.
>>
>> Stefan
> 
> Thanks Stefan.
> 
> After using the instance variables through out i'm still getting the 
> same results for both of method class; the variable value is not 
> changing.
> Here's the code:
> class TestClass
>     def initilize

this should be initialize

>         @col = 'A'
>         @row = 1
>         @maxCol = 'H'
>         @maxRow = 5
>         @myNextCell = ''
>     end
>     def nextcell
> 
>         @col = 'A'
>         @row = 1
>         @maxCol = 'H'
>         @maxRow = 5

You need to get rid of the 4 lines above.

> 
>         if (@col < @maxCol)
>             @myNextCell = @col + @row.to_s
>             @col = @col.next
>             puts("Next Cell is #{@myNextCell}")
>             return @myNextCell
>         else
>             @row.next
>             @myNextCell = @col + @row.to_s
>             @col.next
>             return @myNextCell
>         end
>     end
> 
> tc = TestClass.new
> puts tc.nextcell.inspect
> puts tc.nextcell.inspect

move the 3 lines below the end

> end

This is what I meant:

class TestClass
  # this method is executed if you call TestClass.new
  def initialize
    @col = 'A'
    @row = 1
    @maxCol = 'H'
    @maxRow = 5
    @myNextCell = ''
  end

  def next_cell
    if (@col < @maxCol)
      @myNextCell = @col + @row.to_s
      @col = @col.next
      puts("Next cell is #{@myNextCell}")
    else
      @row = @row.next
      @myNextCell = @col + @row.to_s
      @col = @col.next # this looks wrong
      # (@col increases on every call of
      # next_cell, maybe it should be reset to default ('A')?)
    end
    return @myNextCell
  end
end

tc = TestClass.new
puts tc.inspect
p tc
cellB1 = tc.next_cell
puts cellB1.inspect
puts tc.inspect