Calling a method using a variable name?

ruby-talk
1

Hey folks,

Like many posts have no doubt started.. I'm giving this ruby business
a crack!! :wink:

Now this might be a really bad approach.. but I'll throw it out there.

Here's my simple class.

class Myclass
聽聽def initialize
聽聽end

聽聽def hello
聽聽聽聽puts "hello"
聽聽end

聽聽def bye
聽聽聽聽puts "bye"
聽聽end
end

As expected, works a treat.

friendly = Myclass.new
friendly.hello
friendly.bye

Now, given I now what methods are available, is there a way to do
something similar to this...

methods = ['hello', 'bye']
methods.each { |m| friendly.m }

Regards,

ajt.

2

ajtwatching wrote:

Hey folks,

Like many posts have no doubt started.. I'm giving this ruby business
a crack!! :wink:

Now this might be a really bad approach.. but I'll throw it out there.

Here's my simple class.

class Myclass
  def initialize
  end

  def hello
    puts "hello"
  end

  def bye
    puts "bye"
  end
end

As expected, works a treat.

friendly = Myclass.new
friendly.hello
friendly.bye

Now, given I now what methods are available, is there a way to do
something similar to this...

methods = ['hello', 'bye']
methods.each { |m| friendly.m }

Regards,

ajt.

Look up the __send__ method:

obj.__send__("methodname", arg1, arg2)

3

"ajtwatching" <ajtwatching@gmail.com> writes:

Hey folks,

Like many posts have no doubt started.. I'm giving this ruby business
a crack!! :wink:

Now this might be a really bad approach.. but I'll throw it out there.

Here's my simple class.

class Myclass
  def initialize
  end

  def hello
    puts "hello"
  end

  def bye
    puts "bye"
  end
end

As expected, works a treat.

friendly = Myclass.new
friendly.hello
friendly.bye

Now, given I now what methods are available, is there a way to do
something similar to this...

methods = ['hello', 'bye']
methods.each { |m| friendly.m }

  methods.each{|m| friendly.send m}

路路路

Regards,

ajt.

--
http://kdr2.net

                                               ------yours Killy Draw

4

Or just send which in most cases is preferable. They both do the same
thing (in fact I believe that one is an alias of the other). __send__
is there to cover cases where a class defines a send method for
another purpose.

路路路

On 3/13/07, Timothy Hunter <TimHunter@nc.rr.com> wrote:

Look up the __send__ method:

obj.__send__("methodname", arg1, arg2)

--
Rick DeNatale

My blog on Ruby
http://talklikeaduck.denhaven2.com/

5

Yep, +1. Use #send() rather than #__send__().

Example from irb:

"muppet".send(:to_s)

=> "muppet"

You're telling the String object "muppet" to receive the message
"to_s", in a Smalltalk sense, or, in a Java sense, you're telling the
String object "muppet" to call the method "to_s".

To do it with a variable:

kermit = "to_s"

=> "to_s"

"muppet".send(kermit)

=> "muppet"

Badda bing badda boom.

路路路

--
Giles Bowkett
http://www.gilesgoatboy.org

http://giles.tumblr.com/

On 3/14/07, Rick DeNatale <rick.denatale@gmail.com> wrote:

On 3/13/07, Timothy Hunter <TimHunter@nc.rr.com> wrote:

> Look up the __send__ method:
>
> obj.__send__("methodname", arg1, arg2)

Or just send which in most cases is preferable. They both do the same
thing (in fact I believe that one is an alias of the other). __send__
is there to cover cases where a class defines a send method for
another purpose.

--
Rick DeNatale

My blog on Ruby
http://talklikeaduck.denhaven2.com/