105 lines
2.0 KiB
Swift
105 lines
2.0 KiB
Swift
import UIKit
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// 类的属性有初始值的时候，默认会有一个 init() 的初始化器
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//class Size {
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// var width: Int = 0
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// var height: Int = 0
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//}
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// 等价于
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//class Size {
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// var width: Int
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// var height: Int
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//
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// init() {
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// width = 0
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// height = 0
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// }
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//}
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class Size {
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var width: Int = 0
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var height: Int = 0
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// 指定初始化器（主要初始化器）
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// 用户指定完初始化器之后，会覆盖掉原来的 init()初始化器
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init(width: Int, height: Int) {
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self.width = width
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self.height = height
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}
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// 便捷初始化器
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convenience init(width: Int) {
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self.init(width: width, height: 0)
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}
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}
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var s1 = Size(width: 10, height: 20)
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var s2 = Size(width: 30)
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class Person {
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var age: Int
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// 指定初始化器
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init(age: Int) {
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self.age = age
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}
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// 便捷初始化器
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convenience init() {
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self.init(age: 0)
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}
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}
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class Student: Person {
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var score: Int
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// 指定初始化器调用直系父类的初始化器
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init(age: Int, score: Int) {
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self.score = score
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// super.init 方法放到最后
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super.init(age: age)
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}
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// 便捷初始化器调用便捷初始化器
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convenience init() {
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self.init(score: 0)
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}
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// 便捷初始化器调用指定初始化器
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convenience init(score: Int) {
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self.init(age: 0, score: score)
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}
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}
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class Animal {
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var legs: Int
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var name: String
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var age: Int
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init(name: String, age: Int, legs: Int) {
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self.legs = legs
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self.age = age
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self.name = name
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}
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init(name: String, age: Int) {
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self.legs = 4
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self.age = age
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self.name = name
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}
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convenience init(name: String) {
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self.init(name: name, age: 1, legs: 4)
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}
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}
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class Cat: Animal {
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}
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var cat = Cat(name: "淘气", age: 3, legs: 4)
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var cat1 = Cat(name: "淘气", age: 3)
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var cat2 = Cat(name: "淘气")
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