Swift 函数

• 无参数,无返回值

func sayHelloWorld() {
    print("Hello World")
}
sayHelloWorld() // Hello World

• 参数 返回值

func greet(person:String)->String {
    return "Hello," + person + "!"
}
print(greet(person: "Roy")) // Hello,Roy!

• 多个参数

func introduce(name:String,age:Int,gender:String) {
    print("我的名字是: \(name) ,年龄: \(age),性别: \(gender)")
}
introduce(name: "Roy", age: 18, gender: "男")

• 返回多个值
  得到数组的最大最小值

func getMinandMaxValue(array:[Int])->(min:Int,max:Int) {
    var currentMin = array[0]
    var currentMax = array[0]
    for value in array {
        if value < currentMin {
            currentMin = value
        } else if value > currentMax {
            currentMax = value
        }
    }
    return (currentMin,currentMax)
}
let values = getMinandMaxValue(array: [8, -6, 2, 109, 3, 71])
print(values.min,values.max)

• 默认值

func introduce(name:String,age:Int,gender:String = "男") {
    print("名字: \(name),年龄: \(age),性别: \(gender)")
}
introduce(name: "Roy", age:18 )