Swift Style

Implementing Getters and Setters

Swift allows you to move beyond simple properties to implement custom getters and setters as well as property observers that allow you to react to value changes. Here are some thoughts about preferred practices to use when implementing these features.

Inferring get

When working with read-only computed properties, prefer to remove the get keyword and surrounding braces. The first of the following examples is more concise and just as effective as the second:

var area: Double { // yes
    return width * height
}

var area: Double { // no
    get { return width * height }
}

Overriding newValue and oldValue

Swift setters and property observers supply predefined implicit value argument symbols. ...