What's the difference in calling method vs self.method?

ruby-talk
1

Here's some example code. In method_b, what is the difference in
calling method_a and self.method_a?

class HoHo

  def method_a
    puts "Hello, HoHo"
  end

  def method_b
    method_a
    self.method_a
  end

end

hoho = HoHo.new
hoho.method_b

2

I see no difference indeed, but I'm a Ruby beginner...This is a Ruby
shortcut I think, all method calls inside a class are supposed to be
applied to the called "self" object. Maybe to avoid some "heavy" Python
syntax in wich you'll always see "this.method".
Am I wrong ?

3

Jim wrote:

Here's some example code. In method_b, what is the difference in
calling method_a and self.method_a?

I am sure that the more experienced coders will speak up soon, but until
then Ill do my best.

The self. is implied when you call the method..
just as self.puts or self.gets are often written puts or gets
respectively..

Hope that makes sense.

···

--
Posted via http://www.ruby-forum.com/\.

4

Jim wrote:

Here's some example code. In method_b, what is the difference in
calling method_a and self.method_a?

I just had a thought that it may very well make a difference in the
case of a conflict method names. For example if you had (puposely or
not) created 2 method_a's in the same scope. Make sense?

5

Jim wrote:

Here's some example code. In method_b, what is the difference in
calling method_a and self.method_a?

In Your code it makes no difference, however there are situations when You'll have to explicitly resolve method invocation, consider:

class C
  def meth1
  end

  def meth2
    meth1 # no problem, but..
    meth1=4 # variable assignment
    self.meth1 # so we have to resolve it as a method
  end
end

other thing is operator method invocation:

class D

  def + arg
    p arg
  end

  def meth
    + 2 # Ruby sees it as unary plus, aka +@
    self + 2 # explicit
  end

end

lopex

6

Somewhat related to the above is the following case:

  class Clz
    attr_accessor :myattr
  
    def amethod
      # doesn't work, Ruby treats as local assignment
      # myattr = 5
  
      # We have to be explicit.
      self.myattr = 5
    end
  end

Another area I guess it could make a difference is:

  class ClzToo

    def amethod
      # doesn't work, private methods cannot be called
      # with a receiver.
      # puts self.aprivate

      # So we can only call without 'self'
      puts aprivate
    end

    private

    def aprivate
      "private"
    end
  end

···

On Sat, 31 Dec 2005 19:11:37 -0000, Marcin Mielżyński <lopexx@autograf.pl> wrote:

Jim wrote:

Here's some example code. In method_b, what is the difference in
calling method_a and self.method_a?

In Your code it makes no difference, however there are situations when You'll have to explicitly resolve method invocation, consider:

class C
  def meth1
  end

  def meth2
    meth1 # no problem, but..
    meth1=4 # variable assignment
    self.meth1 # so we have to resolve it as a method
  end
end

other thing is operator method invocation:

class D

  def + arg
    p arg
  end

  def meth
    + 2 # Ruby sees it as unary plus, aka +@
    self + 2 # explicit
  end

end

--
Ross Bamford - rosco@roscopeco.remove.co.uk