IOS_swift_函数用法

1.多个返回值

func x(x:Int, y:Int)->(Int, Int){
let a = x+y
let b = x-y
return (a, b)
}
let (a, b) = x(10, y: 3)
print("a = \(a)")
let val = x(10, y: 3)
print("val = \(val.0)")

2.默认参数

func x(x:Int, y:Int=10)->(Int, Int){
let a = x+y
let b = x-y
return (a, b)
}
x(10)
x(10, y: 3)

3.函数参数

z(y, x: 10, y: 7)

func x(x:Int, y:Int)->(Int, Int){
let a = x+y
let b = x-y
return (a, b)
}

func z(fx:(Int, Int)->(Int,Int), x:Int, y:Int){
let x = fx(x, y).0;
print("x = \(x)")
}

4.关键字inout

func change(inout m:Int){
m = 10;
}
var xx = 2;
change(&xx)
print("xx = \(xx)")