The Switf programming Language 练习代码（3）
//
// main.swift
// classTest
//
// Created by 小强 on 15/12/8.
// Copyright © 2015年 小强. All rights reserved.
//
import Foundation
// 对象和类
class Shape
{
var numberOfSides = 0;
let constNumber = 10;
func simpleDescription() -> String
{
return "A shape with \(numberOfSides) sides."
}
func getNumberOfSides(numberOfSides: Int) //接收参数的方法
{
self.numberOfSides = numberOfSides;
}
};
// 练习 1 使用 let 添加一个常量属性，再添加一个接收一个参数的方法
var shape = Shape();
shape.numberOfSides = 7;
print(shape.simpleDescription());
// 使用 init 来创建一个构造器,deinit 来创建一个析构函数
class NamedShape
{
var numberOfSides: Int = 0;
var name: String;
init (name: String)
{
self.name = name;
}
func simpleDescription() -> String
{
return "A shape with \(numberOfSides) sides.";
}
deinit{} // 析构函数
};
class Square :NamedShape
{
var sideLength: Double = 0;
init(sideLength: Double, name: String)
{
self.sideLength = sideLength;
super.init(name: name)
numberOfSides = 4;
}
func area() -> Double
{
return sideLength * sideLength;
}
override func simpleDescription() -> String {
return "A square with sides of length \(sideLength)."
}
};
let test = Square(sideLength: 5.2, name: "my test square");
print(test.area());
print(test.simpleDescription());
// 练习2 创建 NamedShape 的另一个子类 Circle，构造器接收两个参数，
// 一个是半径一个是名称，实现 area 和 describe 方法
class Circle :NamedShape{
var radius: Double = 0.0;
init(radius: Double, name: String){
self.radius = radius;
super.init(name: name);
}
func area() -> Double{
return 3.14 * radius * radius;
}
override func simpleDescription() -> String {
return "A circle with radius is: \(radius).";
}
}
let circle = Circle(radius: 3.0, name: "my test circle");
print(circle.area());
print(circle.simpleDescription());