传入函数的参数可以简单的用一个数组动态传入
func sumOf(numbers: Int...) -> Int {
var sum = 0
for number in numbers {
sum += number
}
return sum
}
sumOf()
sumOf(42, 597, 12)
sumOf(222,3333,44444,555555)函数可以嵌套使用
func returnFifteen() -> Int {
var y = 10
// 嵌套的函数
func add() {
y += 5
}
// 引用嵌套的函数
add()
return y
}
returnFifteen()一个函数可以返回另一个函数作为它的值
func makeIncrementer() -> (Int -> Int) {
func addOne(number: Int) -> Int {
return 1 + number
}
return addOne
}
//返回addOne(number:Int)->Int{....}给increment
var increment = makeIncrementer()
//传入参数
increment(7)一个函数可以使用另一个函数作为它的传入参数
func hasAnyMatches(list: [Int], condition: Int -> Bool) -> Bool {
for item in list {
if condition(item) {
return true
}
}
return false
}
func lessThanTen(number: Int) -> Bool {
return number < 10
}
var numbers = [20, 19, 7, 12]
hasAnyMatches(numbers, lessThanTen)You can write a closure without a name by surrounding code with braces ({}). Use in to separate the arguments and return type from the body.
var numbers = [20, 19, 7, 12]
//----乘以3方法一
numbers.map({
(number: Int) -> Int in
let result = 3 * number
return result
})
//----乘以3方法2
let mappedNumbers = numbers.map({ number in 3 * number })
mappedNumbers
//----排序
let sortedNumbers = sorted(numbers) { $0 > $1 }
sortedNumbers对象和类
// class + 类名 新建一个类
//{ 属性和方法 定义}
class Shape {
var numberOfSides = 4
let color = "#3b5998"
func simpleDescription() -> String {
return "A shape with \(numberOfSides) sides."
}
func shadow(isShadowOn:Bool) ->String{
if(isShadowOn){
return "This is ON"
}else{
return "This is OFF"
}
}
}
// 首先实例化一个类
// 用class.propert class.method 来引用属性和方法
var shape = Shape()
// 改写属性
shape.numberOfSides = 7
// 调用方法
var shapeDescription = shape.simpleDescription()
var shadow = shape.shadow(true)
//定义类Shape
class Shape {
//定义属性
let color = "#000"
var numberOfSides = 0
var name: String
//初始化
init(name: String) {
self.name = name
}
//定义方法
func simpleDescription() -> String {
return "A shape with \(numberOfSides) sides."
}
}
//新建一个实例化Shape
var shape = Shape(name: "Test_Shape")
//设置属性
shape.numberOfSides = 7
//调用方法
var shapeDescription = shape.simpleDescription()
//子类Square继承自Shape
class Square: Shape {
//添加属性
var sideLength: Double
//自定义初始化方法
init(sideLength: Double, name: String) {
self.sideLength = sideLength
super.init(name: name)
numberOfSides = 4
}
//添加的方法
func area() -> Double {
return sideLength * sideLength
}
//复写父类方法
override func simpleDescription() -> String {
return "A square with sides of length \(sideLength)."
}
}
//实例化一个Square
let test = Square(sideLength: 5.2, name: "my test square")
//调用方法
test.area()
test.simpleDescription()
