From: "Wolfgang Nádasi-Donner" <wonado@...>
Date: 2007-01-27T20:35:11+09:00
Subject: Re: pass by reference?

 >>>>> Code >>>>>

def modifying(a_param)
   a_param = "hi"
end

def modifying2(a_param=a_value)
   a_param = "hi"
end

def modifying3(a_param)
   a_param[0..-1]= "hi"
end

a_value = "low"
modifying a_value
case a_value
when "hi"
   puts "Passed by reference"
when "low"
  puts "Passed by value"
else
  puts "Passed away"
end

a_value = "low"
modifying2 a_value
case a_value
when "hi"
   puts "Passed by reference"
when "low"
  puts "Passed by value"
else
  puts "Passed away"
end

a_value = "low"
modifying3 a_value
case a_value
when "hi"
   puts "Passed by reference"
when "low"
  puts "Passed by value"
else
  puts "Passed away"
end

 >>>>> Output >>>>>

Passed by value
Passed by value
Passed by reference

 >>>>> EoE >>>>>

I would name it somehow "call by assignment of value to local variable", because 
the value of the actual parameter is assigned to the local variable used as a 
formal parameter.

except for "Fixnum" etc. this is a pointer to an object. I one changes the 
object itself, it will work like  "by reference", otherwise only the local 
variable is affected, without having any effect to the outside world.

Wolfgang N�dasi-Donner