标签:size cal default 一个 first init out 控制器 super
//
// ViewController.swift
// swiftT
//
// Created by wjwdive on 2019/1/9.
// Copyright ? 2019年 wjwdive. All rights reserved.
//
import UIKit
struct Size {
var width = 0.0, height = 0.0
init() {
self.init(width: 2.0, height: 2.0)
}
init(width: Double, height: Double){
self.width = width
self.height = height
}
}
class Car {
var speed:Double
init(speed:Double) {
self.speed = speed
}
convenience init() {
self.init(speed: 60.0)
}
}
class Bus: Car {
var wheels : Int
init(wheels: Int) {
self.wheels = wheels
super.init(speed: 120.0)
}
convenience init() {
self.init(wheels: 6)
}
}
struct Vector2D {
var x = 0.0, y = 0.0
}
//声明 自定义的运算符
prefix operator +++
// x 相加,y相减
infix operator +- : AdditionPrecedence
// x平方, y 平方和 按照乘法优先级
//infix operator *^ : MultiplicationPrecedence
//自定义优先级
infix operator *^ : MyPrecendernce
//运算符优先级 设置
precedencegroup MyPrecendernce {
associativity: left
lowerThan: AdditionPrecedence
}
extension Vector2D : Equatable{
//加法运算符重载
static func + (left: Vector2D, right: Vector2D) -> Vector2D {
return Vector2D(x: left.x + right.x, y: left.y + right.y)
}
//一元运算符重载 在z声明运算符函数的时候在关键字之前执行prefix和postfix限定符
static prefix func - (vector: Vector2D) -> Vector2D {
return Vector2D(x: -vector.x, y: -vector.y)
}
//组合运算符的重载, 需要把运算符的左参数设置成 inout 类型,因为这个参数的值会在运算符函数内直接被修改
static func += (left: inout Vector2D, right: Vector2D) {
// left = left + right
left = Vector2D(x: left.x + right.x, y: left.y + right.y)
}
//等价运算符重载 == ,!=
//自定义的类和结构图不接受等价运算符的默认实现,所以想要使用的话需要重载并且遵循标准库的Equatable 协议
static func == (left: Vector2D, right: Vector2D) -> Bool {
return (left.x == right.x) && (left.y == right.y)
}
static func != (left: Vector2D, right: Vector2D) -> Bool {
return !(left.x == right.x) && (left.y == right.y)
}
// 自定义运算符 声明和实现自定义运算符s需要声明是 前置,中置, 后置 (prefix infix postfix)
//例如 定义一个+++ 双倍运算符
static prefix func +++ (vector: Vector2D) -> Vector2D {
return Vector2D(x: vector.x + vector.x, y: vector.y + vector.y)
}
//可以自定义运算符的 优先级和结核性
//声明一个 x相加+ y相减- 的操作符
static func +- (left: Vector2D, right: Vector2D) -> Vector2D {
return Vector2D(x: left.x + right.x, y: left.y - right.y)
}
//自定义平方和 *& 操作符(x 相乘, y 平方和)
static func *^ (left: Vector2D, right: Vector2D) -> Vector2D {
return Vector2D(x: left.x * right.x, y: left.y * right.y + left.y * right.y )
}
}
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
// var size = Size()
// print(size.width, size.height)
// var size2 = Size()
// print(size2.width, size2.height)
self.title = "控制器"
let a: String? = "dd"
if let b = a {
print(type(of: a), type(of: b))
}
let c = a ?? "default"
print(c, type(of: c))
let d = "ddd"
print("d: \(d)")
var str1: String? = "str1"
var str2: String? = "str2"
if let acturalStr1 = str1,let acturalStr2 = str2 {
let count1 = acturalStr1.count, count2 = acturalStr2.count
print(count1, count2)
}
while let acturalStr1 = str1, let acturalStr2 = str2 {
let count1 = acturalStr1.count, count2 = acturalStr2.count
print("22", count1, count2)
break
}
//可选项的隐式展开, swift的初始化类中
var strr: String! = "str!"
let count = strr.count
print("str! count", count)
var strOp: Optional<String> = "str optional"
if let actStrOp = strOp {
let count = actStrOp.count
print(count)
}
print(1.description)
//运算符+ 重载
let vector = Vector2D(x: 3.0, y: 1.0)
let anotherVector = Vector2D(x: 2.0, y: 4.0)
let combinedVector = vector + anotherVector;
print(combinedVector)//Vector2D(x: 5.0, y: 5.0)
//运算符- 重载
let positiveVector = Vector2D(x: 3.0, y: 4.0)
let negativeVector = -positiveVector
print(negativeVector)//Vector2D(x: -3.0, y: -4.0)
//运算符 += 重载
var origional = Vector2D(x: 1.0, y: 2.0)
let vectorToAdd = Vector2D(x: 3.0, y: 4.0)
origional += vectorToAdd
print("+= 重载 : ", origional)//+= 重载 : Vector2D(x: 4.0, y: 6.0)
let v1 = Vector2D(x: 1, y: 2)
let v2 = Vector2D(x: 1, y: 2)
print("== 重载 : ", v1 == v2)//== 重载 : true
let vectorTobeDoubed = Vector2D(x: 1.0, y: 2.0)
let doubleVector = +++vectorTobeDoubed
print("+++ 自定义重载", doubleVector)//+++ 自定义重载 Vector2D(x: 2.0, y: 4.0)
let firstV = Vector2D(x: 1.0, y: 3.0)
let secondV = Vector2D(x: 1.0, y: 1.0)
let result = firstV +- secondV
print("重载 +- : ", result)//重载 +- : Vector2D(x: 2.0, y: 2.0)
let thirdV = Vector2D(x: 1.0, y: 2.0)
let result11 = firstV *^ secondV
print("重载 *^ : ", result11)//重载 *^ : Vector2D(x: 1.0, y: 6.0)
//自定义了优先级,会先算 +-, 后算 *^
let result12 = firstV +- secondV *^ thirdV
print("优先级结合 +- *^ ", result12)//优先级结合 +- *^ Vector2D(x: 2.0, y: 8.0)
}
}
标签:size cal default 一个 first init out 控制器 super
原文地址:https://www.cnblogs.com/wjw-blog/p/12915303.html