Understanding send

ruby-talk
1

class MyNewClass
  attr_accessor :name,:place,:age
end
a=[]
1.upto(3) do
  val=MyNewClass.new
  val.instance_variables.each do |met|
   val.send(met.delete("@")+"=",gets.chomp!)
  end
a<<val
end
a.each do |val|
val.instance_variables.each do |met|
  p val.send(met.delete("@"))
end
end
a.each do |val|
MyNewClass.instance_methods(false).select{
   >v> v =~ /[=$]/
}.each do |met|
  val.send(met,gets.chomp!)
end
end

a.each do |val|
MyNewClass.instance_methods(false).select{
   >v> v =~ /[a-z]$/
}.each do |met|
   p val.send(met)
end
end

hi all,
can any one tell me whats wrong with this code its not working for
val.send(met.delete("@")+"=",gets.chomp!)

if instead of val.send(met.delete("@")+"=",gets.chomp!) i give
val.name=gets.chomp!..... it works

regards
gaurav v bagga

2

The problem is hidden in following lines. There is no problem with
doing send on methods.

class MyNewClass
  attr_accessor :name,:place,:age
end
a=
1.upto(3) do
  val=MyNewClass.new
  val.instance_variables.each do |met|
   val.send(met.delete("@")+"=",gets.chomp!)
  end
a<<val
end

You are trying to define some attributes, through attr_accessor. Now,
what attr_accessor does? It sets couple of instance methods
automatically on your class. So...if you do:
val.instance_variables.each do|x|
p x
end

You will get an empty list. Why? Because your instance variables are
not there yet. What probably you want to do is..get instance_methods
and set your instance_variables there. Until you set them
up..."val.instance_variables" will contain a empty list. and hence all
the subsequent lines will fail.

···

On 11/8/06, gaurav bagga <gaurav.v.bagga@gmail.com> wrote:

a.each do |val|
val.instance_variables.each do |met|
  p val.send(met.delete("@"))
end
end
a.each do |val|
MyNewClass.instance_methods(false).select{
   >v> v =~ /[=$]/
}.each do |met|
  val.send(met,gets.chomp!)
end
end

a.each do |val|
MyNewClass.instance_methods(false).select{
   >v> v =~ /[a-z]$/
}.each do |met|
   p val.send(met)
end
end

hi all,
can any one tell me whats wrong with this code its not working for
val.send(met.delete("@")+"=",gets.chomp!)

if instead of val.send(met.delete("@")+"=",gets.chomp!) i give
val.name=gets.chomp!..... it works

regards
gaurav v bagga

--
There was only one Road; that it was like a great river: its springs
were at every doorstep, and every path was its tributary.