Global variables usage

ruby-talk
1

I declared two files.One to hold the value of a global variable.And the
other to print it.

1)to hold variables (var.rb)

Code:

    $foo = 500

2) to print the global variable (gprint.rb)

Code:
    loop do
    puts $foo
    end

But when I print it ,I get the value "nil" being printed not 500.What
could be the problem?

I did read some tutorials online but dint help.Could some please tell
why I am not able to access the global variable between two .rb files in
the same folder?

Please let me know.

···

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Posted via http://www.ruby-forum.com/.

2

where in this code (gprint.rb) does it say that you are accessing the
file var.rb ?
read on require and load...

best regards -botp

···

On Fri, Feb 19, 2010 at 3:02 PM, di vi <infibit@gmail.com> wrote:

I declared two files.One to hold the value of a global variable.And the
other to print it.

1)to hold variables (var.rb)

Code:

$foo = 500

2) to print the global variable (gprint.rb)

Code:
loop do
puts $foo
end

3

botp wrote:

···

On Fri, Feb 19, 2010 at 3:02 PM, di vi <infibit@gmail.com> wrote:

2) to print the global variable (gprint.rb)

Code:
� �loop do
� �puts $foo
� �end

where in this code (gprint.rb) does it say that you are accessing the
file var.rb ?
read on require and load...

best regards -botp

Load and require execute the complete program..I want only the value of
global variables to change in the respective .rb file.

--
Posted via http://www.ruby-forum.com/\.

4

Well, there's an obvious solution to that: place the global variable
in a file on its own which you load from all places that need it.
However, I am not sure that this is generally a good idea. What do
you need that for?

Kind regards

robert

···

2010/2/19 di vi <infibit@gmail.com>:

botp wrote:

On Fri, Feb 19, 2010 at 3:02 PM, di vi <infibit@gmail.com> wrote:

2) to print the global variable (gprint.rb)

Code:
� �loop do
� �puts $foo
� �end

where in this code (gprint.rb) does it say that you are accessing the
file var.rb ?
read on require and load...

best regards -botp

Load and require execute the complete program..I want only the value of
global variables to change in the respective .rb file.

--
remember.guy do |as, often| as.you_can - without end
http://blog.rubybestpractices.com/

5

> botp wrote:
>>>
>>> 2) to print the global variable (gprint.rb)
>>>
>>> Code:
>>> � �loop do
>>> � �puts $foo
>>> � �end
>>
>> where in this code (gprint.rb) does it say that you are accessing the
>> file var.rb ?
>> read on require and load...
>>
>> best regards -botp
>
> Load and require execute the complete program..I want only the value of
> global variables to change in the respective .rb file.

Well, there's an obvious solution to that: place the global variable
in a file on its own which you load from all places that need it.
However, I am not sure that this is generally a good idea. What do
you need that for?

. . . or edit the file you're loading/requiring so that it will only
conditionally execute code in the file if the file is executed directly,
and not if it is called as a library using load or require. For
instance:

    > cat included_file.rb
    #!/usr/bin/env ruby
    $foo = 'foo'
    $bar = 'bar'
    if $0 == __FILE__
      # code to be executed if file
      # called directly for execution
    end

    > cat including_file.rb
    #!/usr/bin/env ruby
    load 'included_file.rb'
    if $0 = __FILE__
      # do stuff with $foo
      # do stuff with $bar
    end

Apologies if I'm off-base -- I haven't read the whole thread in detail,
because I just rejoined the list after a hiatus.

···

On Fri, Feb 19, 2010 at 09:00:47PM +0900, Robert Klemme wrote:

2010/2/19 di vi <infibit@gmail.com>:
>> On Fri, Feb 19, 2010 at 3:02 PM, di vi <infibit@gmail.com> wrote:

--
Chad Perrin [ original content licensed OWL: http://owl.apotheon.org ]