Swift

//: Playground - noun: a place where people can play

import UIKit

// 定义一个数组
var userScores:[Int]? = [12, 990, 572, 3258, 9999, 1024, 666]
userScores = userScores ?? []

// 定义一个函数获取数组中最大值和最小值
// 注意: (maxScores:Int, minScores:Int)? 和 (maxScores:Int?, minScores:Int?) 是两个完全不同的表达意思
// 前者表示可选性元组, 后者表示元组中的两个值为可选性,而元组本身不是可选性
func maxminScores(scores:[Int]) -> (maxScores:Int, minScores:Int)?
{
    // 判断传进来的数组是否为空
    if scores.isEmpty {
        return nil
    }
    
    // 获取最大最小值
    var curMax = scores[0], curMin = scores[0]
    for score in scores[1..<scores.count] {
        curMax = max(curMax, score)
        curMin = min(curMin, score)
    }
    return (curMax, curMin)
}

if let result = maxminScores(userScores!) {
    print("The maxScores is (result.maxScores), the minScores is (result.minScores)")
}