swift 函数

//函数func sayAfternoon(personName: String) -> String {    let say = "Hello afternoon " + personName + "!"    return say}sayAfternoon("王丽媛")//多参量函数func sayHello(personName: String, isExsit: Bool) {    if isExsit {        print ("已经说过了")    } else {        print ("hello " + personName)    }}sayHello("jiawei", isExsit: true)//多重返回值函数func minMax(array: [Int]) -> (min: Int, max: Int) {    var currentMin = array[0]    var currentMax = array[0]    for value in array[1..currentMax {

currentMax = value

}

}

return (currentMin, currentMax)

}