creating and naming variables dynamic

[Tarscher]

Hi all,

I want to create a variable dynamic. I have defined some classes and
depending on data I get from a database I need to construct an object
eg:

now I do

if type=="car"
variab = Car.new
elsif type="boat"
variab = Boat.new
end

can I do something like
variab = Instance.new(type)


Following this: can I give dynamic variablenames?
now I do
if type=="car"
car_string = Car.new
elsif type="boat"
boat_string = Boat.new
end

can I do something like
dynamicpart_string = Instance.new(type)

Regards,
Stijn

 

[David A. Black]

Hi --

Hi all,

I want to create a variable dynamic. I have defined some classes and
depending on data I get from a database I need to construct an object
eg:

now I do

if type=="car"
variab = Car.new
elsif type="boat"
variab = Boat.new
end

can I do something like
variab = Instance.new(type)


Following this: can I give dynamic variablenames?
now I do
if type=="car"
car_string = Car.new
elsif type="boat"
boat_string = Boat.new
end

can I do something like
dynamicpart_string = Instance.new(type)

Fred Cheung has answered this post for you on the Rails mailing list.


David

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See http://www.rubypal.com for details and updates!

 

[Peter Szinek]

[Note: parts of this message were removed to make it a legal post.]

if type can be either 'car' or 'boat' i.e. lowercase strings:

my_class = Object.const_get(type.capitalize)

and then

my_class.new

etc.

alternatively, you can look into active_support, where you have stuff
like
=> "aa"

HTH,
Peter
___
http://www.rubyrailways.com
http://scrubyt.org

 

[Robert Klemme]

Hi all,

I want to create a variable dynamic. I have defined some classes and
depending on data I get from a database I need to construct an object
eg:

now I do

if type=="car"
variab = Car.new
elsif type="boat"
variab = Boat.new
end

can I do something like
variab = Instance.new(type)

More options

factory = {
"car" => Car,
"boat" => Boat,
}

var = factory[type].new

Following this: can I give dynamic variablenames?
now I do
if type=="car"
car_string = Car.new
elsif type="boat"
boat_string = Boat.new
end

can I do something like
dynamicpart_string = Instance.new(type)

Better use a Hash for this

vars = {}
vars[type] = factory[type].new

Cheers

robert

 

[Bernardo Monteiro Rufino]

[Note: parts of this message were removed to make it a legal post.]

You can try methods instead of dynamic variables, but the best option is the
one above with hash.

self.class.senddefine_method, type){Object.const_get(type.capitalize);}