Check if 2 objects are equal

ruby-talk
1

Hi
I havea a class with this structure. how do i check if 2 objects
instanialted from this class are equal. they could be separate
instantialtion but have exactly the same values?

class SymbolObject

    def initialize(symb)
       puts symb
      @symbol=symb

@name=@exchange=@news=@summary=@sector=@industry=@category=@otherInfo=@scanType=""
      @markedBad=false
    end
    attr_accessor :symbol,:name ,:exchange, :news, :summary, :sector,
:industry,:category,:markedBad,:scanType,:otherInfo;
    def to_s
      return @symbol + @news + @exchange + @name
    end
    
end

2

If you want to define equivalence for your classes, you really need to
do so yourself.

The easiest way is to make the class Comparable, and define your own
<=> operator. You can be as simple or as complex as you like:

class MyClass
  include Comparable

  attr_accessor :my_age, :my_first_name, :my_last_name

  def initialize(age,first_name,last_name)
    @my_age = age.to_i
    @my_first_name = first_name
    @my_last_name = last_name
  end

  def <=>(other)
    # if the other class being compared is nil, we aren't equivalent
    return nil if other.nil?

    # Simple case, if both objects have same objectid, they are the same
    return 0 if object_id == other.object_id

    # Define a heirarchy of tests for this class
    if (@my_age == other.my_age)
      if (@my_first_name <=> other.my_first_name) == 0
        return @my_last_name <=> other.my_last_name
      else
        return @my_first_name <=> other.my_first_name
      end
    else
      return @my_age <=> other.my_age
    end
  end

end

3

N Okia wrote:

If you want to define equivalence for your classes, you really need to
do so yourself.

The easiest way is to make the class Comparable, and define your own
<=> operator. You can be as simple or as complex as you like:

class MyClass
include Comparable

attr_accessor :my_age, :my_first_name, :my_last_name

def initialize(age,first_name,last_name)
   @my_age = age.to_i
   @my_first_name = first_name
   @my_last_name = last_name
end

def <=>(other)
   # if the other class being compared is nil, we aren't equivalent
   return nil if other.nil?

   # Simple case, if both objects have same objectid, they are the same
   return 0 if object_id == other.object_id

   # Define a heirarchy of tests for this class
   if (@my_age == other.my_age)
     if (@my_first_name <=> other.my_first_name) == 0
       return @my_last_name <=> other.my_last_name
     else
       return @my_first_name <=> other.my_first_name
     end
   else
     return @my_age <=> other.my_age
   end
end

end

The simplest way to do this is:

def <=>(other)
  return [@my_age, @my_first_name, @my_last_name] <=> [other.age, other.my_first_name, other.my_last_name]
end