元组
var t1 = (1, 2, 3)
print(t1.0, t1.1, t1.2)
var(a, b, c) = (4, 5, 6)
print(a, b ,c)
let t2 = (first: 1, second: 2, third: 3)
print(t2.1, t2.second)
(a, b, c) = (c, b, a)
print(a, b, c)
func returnTuple() -> (Int, Int, Int) {
return (1, 3, 5)
}
var (d, e, f) = returnTuple()
print(d, e, f)
defer延时执行
func delayCall(){
var i = 0
defer{
print("First defer：",i)
}
i = 1
defer{
print("Second defer：",i)
}
i = 2
print("First：",i)
print("Second!!!")
}
delayCall()
Any可以用任意类型，而AnyObject只能用于class类型
class A{
}
var arr01 = [Any]()
arr01.append(1)
arr01.append(2.0)
arr01.append("ab")
var a1:Double = arr01[1] as! Double
var arr02 = [AnyObject]()
let sa = A()
arr02.append(sa)
@autoclosure
func executeAutoclosure(@autoclosure c: () -> Bool){
if c() {
print("True")
}else{
print("False")
}
}
executeAutoclosure(1 > 3)
inout类型的参数
- 只能传递变量，并且加&
- 可以在函数里面修改函数的参数，同时影响外面的变量
var (b1, b2) = (1, 2)
func swap(inout a: Int, inout b: Int){
(a, b) = (b, a)
}
swap(&b1, b: &b2)
print(b1, b2)
lazy
1.必须要第一次使用时才执行
2.只会执行一次
var ani = Animal()
print(ani.name)
泛型
//泛型函数
func compare<T: Equatable>(a: T, b: T) -> Bool{
return a == b
}
print(compare(1, b: 1.0))
print(compare(1, b: "1"))
func printV<T>(a: T) {
print(a)
}
printV(1)
printV(2.0)
printV("abc")
//泛型类
class Stack<T>{
var arr = [T]()
func push(a:T){
arr.append(a)
}
func pop() -> T{
return arr.removeLast()
}
}
var arr1 = Stack<Int>()
arr1.push(12)
arr1.push(34)
print(arr1.pop())
print(arr1.pop())
