import UIKit  

//数组问题  

struct student {  

var name ="123"  

}  

var str ="Hello, playground"  

//将多个数组合成一个数组  

let array = [[1,2,4,],[3,5],[565,33]]  

//let arrayMap = array.map{$0}  

let arrayFlat = [[123,123],[444]].flatMap{ $0 }  

print(arrayFlat)  



//分离出条件内的数字并和成数组  

let arrayFilter = [1,2,3,4,5,6,20]  

let tempFilter = arrayFilter.filter{ $0 % 2 == 0 }  

print(tempFilter)  



//获取数组的和  

let sumArray = [2,3,5,6,7]  

let tempSum = sumArray.reduce(0){ $0 + $1}  

print(tempSum)  



//从类里面遍历出来  

var oneS = student.init()  

oneS.name = "1"  

var oneS1 = student.init()  

oneS1.name = "2"  

var oneS2 = student.init()  

oneS2.name = "3"  

let students = [oneS,oneS1,oneS2]  

let endS = students.filter { (student) -> Bool in  

return student.name == "2"  

}  

if let endA = endS.last {  

print(endS.last)  

}  



//取出空数组  

let nilArray = [[],[23,322],[4,3,4],[],[666,777],[]]  

let tempNilArray = nilArray.filter { (array) -> Bool in  

return array.count > 0  

}  

print(tempNilArray)  



//forEach遍历数据  

let testArrA = [1,4,5,6,1]  

let testArrB = [1,2,3,4,5]  

let testArrC = ["a","b","c","D"]  

(2..

    print(countT)  

}  



//遍历  

testArrC.enumerated().forEach { (oneStr) in  

print(oneStr.element)  

}  



//从某一点这个点开是，分离成两个数组，并去掉当前的元素  

testArrA.split(separator: 4)  

testArrC.split(separator: "b")  

//条件分离  

testArrA.split { (tempInt) -> Bool in  

return tempInt <= 1  

}  



//删除索引之前的对象  

testArrC.dropFirst(0)  

testArrC.dropLast(1)  



//修改数组元素内容  

print(testArrC.map{$0.lowercased()})  



//排序  

print(testArrC.sorted(by: < ))  

print(testArrB.sorted(by: < ))  



//倒序  

print(Array(testArrA.reversed()))  



//prefix,取前几位的值  

print(testArrA.prefix(3))  



//suffix，取后几位的值  

print(testArrA.suffix(1))  



// 运算符重载  

func == (stu1: student,stu2: student) -> Bool {  

if stu1.name == stu2.name {  

return true  

    }  

return false  

}  



let isEqual = oneS1 == oneS  

let threeArr = [1] + [3] + [1,0,88]  



let befor =1  

let later = ~1  

print(later)  



//枚举  

enum WeekType {  

case One  

case Two  

}