Computed read-only property vs function in Swift-优快云博客

本文探讨了在Swift中选择使用只读计算属性而非方法的原因。通过一个Vehicle类的例子，对比了属性和方法的不同之处，并讨论了它们在语义、简洁性和清晰度方面的差异。

In the Introduction to Swift WWDC session, a read-only property description is demonstrated:

class Vehicle {
    var numberOfWheels = 0
    var description: String {
        return "\(numberOfWheels) wheels"
    }
}

let vehicle = Vehicle()
println(vehicle.description)

Are there any implications to choosing the above approach over using a method instead:

class Vehicle {
    var numberOfWheels = 0
    func description() -> String {
        return "\(numberOfWheels) wheels"
    }
}

let vehicle = Vehicle()
println(vehicle.description())

It seems to me that the most obvious reasons you would choose a read-only computed property are:

Semantics - in this example it makes sense for description to be a property of the class, rather than an action it performs.
Brevity/Clarity - prevents the need to use empty parentheses when getting the value.
Clearly the above example is overly simple, but are there other good reasons to choose one over the other? For example, are there some features of functions or properties that would guide your decision of which to use?

N.B. At first glance this seems like quite a common OOP question, but I'm keen to know of any Swift-specific features that would guide best practice when using this language.

转载于:https://www.cnblogs.com/davidyff/p/5383350.html