struct Color { let red, green, blue: Double init(red: Double, green: Double, blue: Double) { self.red = red self.green = green self.blue = blue } init(white: Double) { red = white green = white blue = white } } // 创建一个新的Color实例，通过三种颜色的外部参数名来传值，并调用构造器 let magenta = Color(red: 1.0, green: 0.0, blue: 1.0) print("red 值为: \(magenta.red)") print("green 值为: \(magenta.green)") print("blue 值为: \(magenta.blue)") // 创建一个新的Color实例，通过三种颜色的外部参数名来传值，并调用构造器 let halfGray = Color(white: 0.5) print("red 值为: \(halfGray.red)") print("green 值为: \(halfGray.green)") print("blue 值为: \(halfGray.blue)")