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


#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

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.


#3

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 ?


#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

On Sat, 31 Dec 2005 19:11:37 -0000, Marcin MielżyÅ?ski
removed_email_address@domain.invalid
wrote:

end
class D
end

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

#6

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