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Alex Atwater
2,624 Points“_” vs “.” with variables
What is the difference when accessing a class instance variable when using _variable vs self.variable? I was writing a setter method and self.variable = anotherVariable didn’t work, yet _variable = anotherVariable worked… Why is that?
2 Answers
eirikvaa
18,015 PointsThe difference between accessing instance variables with _instanceVariable and accessing with self.instanceVariable is that _instanceVariable is accessing the instance variable directly. The reason you couldn't set the instance variable in the setter method by writing self.instanceVariable = anotherVariable is that you can't set the instance variable in the setter method with the setter method. It just doesn't work that way. When you are using self.instanceVariable you are using the setter method to access the instance variable rather than accessing it directly.
You would access your instance variables by doing _instanceVariable only in the getter, setter and init methods. Anywhere else you would write self.instanceVariable.
Hope this clears things up.
Alex Atwater
2,624 PointsYes it makes sense! Thanks a ton!