Re: variables and scope

You are getting a -1 because you are using local variables. Thus, the n =
within your def is not the same as the n within your class.
Since you declared n to be -1 in your def, that is what your program =
responded with, a -1.
You need to initialize an instance variable that will be available =
throughout the class.

You can also make your code more utilitarian with a parameter value that =
can be changed any time you create a new instance.
Try the following:

class Test

  def initialize(n)
    @n =3D n
  end

  def pt
    puts "hi there"
    @n -=3D 1
  end
end

t =3D Test.new(100)
puts t.pt

This way, you are not tied down to the value 100, but can use any value =
you want.
I am new at this game and just taking the baby steps, but this seemed to =
work.

Lauren



On Feb 5, 2011, at 12:15 AM, Stu wrote:

> take note of the usage of @ for scope as well as the special
> initialize method used as a constructor for the object.
>=20
> also note note you common bug/mistake. Your where setting n to
> negative one. you need to use n =3D n + -1 or shorthand version below =
is
> n +=3D -1
>=20
> class Test
>  def initialize
>  @n =3D 100
>  end
>=20
>  def pt
>    p "hi there"
>    @n +=3D -1
>  end
> end
>=20
> t =3D Test.new
> puts t.pt
>=20
> If you would like to know more have a look at attr_* in ruby
>=20
> Good luck with your classes
>=20
> ~Stu
>=20
>=20
> On Fri, Feb 4, 2011 at 10:17 PM, Mike 1. <[e-mail]> =
wrote:
>> Hi all,
>>=20
>>  I would be asking my instructor this question be she is not =
available
>> on
>> the weekends...
>>=20
>>  How do I make "n" available from anywhere inside the class? I need =
to
>> keep the values in n from call to call.
>>=20
>>  When calling the method "pt", "n" acts as if it was not declared =
above.
>>=20
>>  I get -1 instead of what I wish for ... 99.
>>=20
>>  Thanks in advance,
>>=20
>>  Mike
>>=20
>> class Test
>> n=3D100
>>=20
>>  def pt
>>   puts "hi there"
>>   n=3D-1
>>  end
>>=20
>> end
>>=20
>> t =3D Test.new
>> puts t.pt
>>=20
>> --
>> Posted via http://www.ruby-forum.com/.
>>=20
>>=20
>=20