I struggled with the concept of self in Ruby for a little longer than necessary I believe. So, I wanted to add to the
literature out there so that any newcomer may not get held up on it for as long as I did.
In short - and skipping all the nuances - self refers to that which it is called on.
What does that mean though?
def run_through_snow
self
end
Okay what is self referring to here? The answer I kept running into was, “It is refferring to whatever object the method is called on.” But this didn’t make things clear for me. Let’s put it into context.
Imagine you have an instance of a Dog (class) set to a variable “Skimpy.”
Skimpy = Dog.new("Skimpy") ## this name is being set as an instance variable @name
Next, let’s say that we want to call the run_through_snow method from earlier on the variable Skimpy?
self is equal to #<Dog:000000000000 @name="Skimpy">
My mind had trouble grasping this until I used binding.pry and actually checked the value of self and saw things for myself.
If you set a binding.pry in the method, such as:
def run_through_snow
self
binding.pry
end
When you drop into pry you can see for yourself.
self will return the instance of the Dog class we created earlier.
#<Dog:000000000000 @name="Skimpy">
self.name will return what?
Exactly
self.name will return “Skimpy”