Swift实战篇

Swift语法二

1.可选元组解决函数返回值空数组问题

   func minMax(array: [Int]) -> (min: Int, max: Int)? {
        if array.isEmpty { return nil}
        var minValue = array[0]
        var maxValue = array[0]
        for value in array[1..<array.count] {
            if minValue < value {
                minValue = value
            }else if value > maxValue{
                maxValue = value
            }
        }
        return (minValue,maxValue)
    }

2.inout解决函数输入输出参数在函数体可变

func swapNumber(_ a:  inout Int, _ b: inout Int) {
    let  temp = a
    a = b
    b = temp
}