Hey All,
If I have the name of a class in a string var, is it possible to get a
new instance of that class (and if so, how)? The following do *not*
work:
my_string = "Hash"
my_object = Class(my_string)
my_object = Class.new(my_string)
my_object = Object.new(my_string)
Thanks!
-Roy
my_object = Object.const_get(my_string.to_sym).new
(The to_sym is mandatory in ruby 1.9.)
Fred
Le 24 janvier 2009 à 02:12, rpardee@gmail.com a écrit :
Hey All,
If I have the name of a class in a string var, is it possible to get a
new instance of that class (and if so, how)? The following do *not*
work:my_string = "Hash"
my_object = Class(my_string)
my_object = Class.new(my_string)
my_object = Object.new(my_string)
--
Any time tomorrow a part of me will die
And a new one will be born
Any time tomorrow I'll get sick of asking why
Sick of all the darkness I have worn (K's Choice, Shadow Man)
"rpardee@gmail.com" <rpardee@gmail.com> writes:
Hey All,
If I have the name of a class in a string var, is it possible to get a
new instance of that class (and if so, how)? The following do *not*
work:my_string = "Hash"
my_object = Class(my_string)
my_object = Class.new(my_string)
my_object = Object.new(my_string)
Class names are used to define constants in the Module module:
irb(main):014:0> className="Hash"
"Hash"
irb(main):015:0> Module.constants.member?(className)
true
Therefore you should be able to get the class with:
irb(main):016:0> Module.class_eval(className)
Hash
and make an instance with:
irb(main):017:0> Module.class_eval(className).new
{}
--
__Pascal Bourguignon__
Awesome cool--looks like I can even pass arguments into new() (which
would have been my next question).
Thanks very much!
-Roy
On Jan 23, 5:25 pm, "F. Senault" <f...@lacave.net> wrote:
Le 24 janvier 2009 02:12, rpar...@gmail.com a crit :
> Hey All,
> If I have the name of a class in a string var, is it possible to get a
> new instance of that class (and if so, how)? The following do *not*
> work:> my_string = "Hash"
> my_object = Class(my_string)
> my_object = Class.new(my_string)
> my_object = Object.new(my_string)my_object = Object.const_get(my_string.to_sym).new
(The to_sym is mandatory in ruby 1.9.)
Fred
--
Any time tomorrow a part of me will die
And a new one will be born
Any time tomorrow I'll get sick of asking why
Sick of all the darkness I have worn (K's Choice, Shadow Man)
Hi --
On Sat, 24 Jan 2009, F. Senault wrote:
Le 24 janvier 2009 à 02:12, rpardee@gmail.com a écrit :
Hey All,
If I have the name of a class in a string var, is it possible to get a
new instance of that class (and if so, how)? The following do *not*
work:my_string = "Hash"
my_object = Class(my_string)
my_object = Class.new(my_string)
my_object = Object.new(my_string)my_object = Object.const_get(my_string.to_sym).new
(The to_sym is mandatory in ruby 1.9.)
I don't think so:
$ ruby19 -ve 'p Object.const_get("String")'
ruby 1.9.1 (2008-12-30 patchlevel-0 revision 21203) [i386-darwin9.5.0]
String
David
--
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Coming in 2009: The Well-Grounded Rubyist (http://manning.com/black2\)
http://www.wishsight.com => Independent, social wishlist management!
Na.
$ ruby_dev -ve 'p File.const_get("Stat")'
ruby 1.9.1 (2008-12-30 patchlevel-0 revision 21203) [i386-darwin9.6.0]
File::Stat
Ruby's a pretty smart gal. 
James Edward Gray II
On Jan 23, 2009, at 7:28 PM, F. Senault wrote:
my_object = Object.const_get(my_string.to_sym).new
(The to_sym is mandatory in ruby 1.9.)
You are, of course, perfectly right. I should do my tests _after_ the
coffee... 
Fred
Le 24 janvier à 03:16, James Gray a écrit :
On Jan 23, 2009, at 7:28 PM, F. Senault wrote:
my_object = Object.const_get(my_string.to_sym).new
(The to_sym is mandatory in ruby 1.9.)
Na.
--
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