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Start your free trialJoe Nguyen
25,189 PointsWhat are Computed Properties?
What are computed properties and what are they used for?I am just asking to understand what they are better so any answers would be helpful!
2 Answers
Steven Parker
231,248 PointsComputed properties are data items that you want to make available that differ from what is actually stored, but can be created using them. For example, an object may store a property for first and last name, but may have a computed property that returns the full name. Or it may store only base price and a tax rate, but have a computed property that returns the after-tax price.
Michael Santos
704 PointsI understand your first/last-name example well. Just to be clear, in our code example, by removing the 'set' keyword from the Location property definition, and making the 'get' custom implemented, I assume we now say the property is no longer an auto-implemented property? In doing so, does this mean that there is no longer an implicit Location variable created "under the hood" for us? I completely understand the rationale for doing this from the perspective of not wanting Invader class users to have to know impl. details like havign to update Location each time _pathStep is incremented, I'm just a little hazy on why this is called a "computed property", in comparison to your first/last-name example which seems more obvious.
Also, do all computed properties by definition not have a setter, or are there exceptions?
Joe Nguyen
25,189 PointsJoe Nguyen
25,189 PointsThank you ,Steven :]