1、元组数据
fun main() {
/**-------------------- 二元元组 --------------------*/
val pair = Pair<String, Int>("张三", 20)
println("(${pair.first}, ${pair.second})")
//(张三, 20)
val pair2 = "李四" to 25
println("(${pair2.first}, ${pair2.second})")
println(pair2.toString())
//(李四, 25)
/**-------------------- 三元元组 --------------------*/
val triple = Triple<String, Int, Boolean>("王五", 18, true)
println("(${triple.first}, ${triple.second}, ${triple.third})")
println(triple.toString())
//(王五, 18, true)
}
2、区间 Range
fun main() {
/**-------------------- 1、区间定义 --------------------*/
val range1: IntRange = 1..10
val range2: IntRange = IntRange(1, 10)
val range3: IntRange = 1.rangeTo(10)
val range4: LongRange = 1L..10L
val range5: LongRange = LongRange(1, 10)
val range6: LongRange = 1L.rangeTo(10L)
val range7: CharRange = 'a'..'z'
val range8: CharRange = CharRange('a', 'z')
val range9: CharRange = 'a'.rangeTo('z')
//until 半开半闭区间
val range: IntRange = 1 until 100 //[1, 100)
/**-------------------- 2、区间遍历 --------------------*/
for (i in range1) {
print("$i ")
}
println()
//1 2 3 4 5 6 7 8 9 10
for((index, i) in range1.withIndex()){
print("($index, $i) ")
}
println()
//(0, 1) (1, 2) (2, 3) (3, 4) (4, 5) (5, 6) (6, 7) (7, 8) (8, 9) (9, 10)
range1.forEach {
print("$it ")
}
println()
//1 2 3 4 5 6 7 8 9 10
range1.forEachIndexed { index, i ->
print("($index, $i) ")
}
println()
//(0, 1) (1, 2) (2, 3) (3, 4) (4, 5) (5, 6) (6, 7) (7, 8) (8, 9) (9, 10)
/**-------------------- 3、反向区间 --------------------*/
val range10: IntProgression = 10 downTo 1
range10.forEach {
print("$it ")
}
println()
//10 9 8 7 6 5 4 3 2 1
val range11: LongProgression = 10L downTo 1L
range11.forEach {
print("$it ")
}
println()
//10 9 8 7 6 5 4 3 2 1
val range12: CharProgression = 'f' downTo 'a'
range12.forEach {
print("$it ")
}
println()
//f e d c b a
/**-------------------- 4、区间反转 --------------------*/
val range13 = range1.reversed()
range13.forEach {
print("$it ")
}
println()
//10 9 8 7 6 5 4 3 2 1
/**-------------------- 5、区间步长 --------------------*/
val range14 = 1..100 step 10
val range15 = IntRange(1, 100) step 10
val range16 = 1.rangeTo(100) step 10
val range17 = 100 downTo 1 step 10
val range18 = range1.reversed() step 10
range14.forEach {
print("$it ")
}
println()
//1 11 21 31 41 51 61 71 81 91
//for 循环里面也可以使用 step 步长
for (i in range1 step 2){
print("$i ")
}
println()
//1 3 5 7 9
}
3、数组 Array
fun main() {
/**-------------------- 1.数组定义 --------------------*/
//（1）使用 arrayOf 创建
val arr0: Array<String> = arrayOf("张三", "李四", "王五")
val arr1: Array<Int> = arrayOf(10, 20, 30)
val arr2: Array<Char> = arrayOf('a', 'b', 'c')
val arr3: Array<Any> = arrayOf("张三", 10, 'a')
//（2）使用构造函数创建具体类型和容量的数组
val intArray = IntArray(4)
val intArray1 = IntArray(4) { 0 }//数组长度为4并且全部初始化为0
val booleanArray = BooleanArray(4)
val byteArray = ByteArray(4)
val shortArray = ShortArray(4)
val charArray = CharArray(4)
val floatArray = FloatArray(4)
val doubleArray = DoubleArray(4)
val longArray = LongArray(4)
//注：除八大基本数据类型之外的对象数据类型只能通过 arrayOf 创建，例如 String 数组
/**-------------------- 2.数组的遍历 --------------------*/
for (s in arr0) {
print("$s ")
}
println()
//张三 李四 王五
for ((index, s) in arr0.withIndex()) {
print("($index, $s) ")
}
println()
//(0, 张三) (1, 李四) (2, 王五)
arr3.forEach {
print("$it ")
}
println()
//张三 10 a
arr3.forEachIndexed { index, s ->
print("($index, $s) ")
}
println()
//(0, 张三) (1, 10) (2, a)
/**-------------------- 3.数组元素的获取 --------------------*/
val temp0 = arr0.get(0)
val temp1 = arr0[0]
println("temp0=$temp0 temp1=$temp1")
/**-------------------- 4.数组元素的修改 --------------------*/
arr0[0] = "马六"
arr0.set(1, "何七")
arr0.forEach {
print("$it ")
}
println()
//马六 何七 王五
/**-------------------- 5.其他 api --------------------*/
val array = arrayOf("张三", "李四", "王五", "张三", "李四", "王五")
//（1）返回第一个匹配元素的角标，如果没有找到则返回-1
val index11 = array.indexOf("张三")
val index12 = array.indexOf("马六")
println("index11=$index11 index12=$index12")
//index11=0 index12=-1
//（2）返回最后一个匹配元素的角标，如果没有找到则返回-1
val index21 = array.lastIndexOf("张三")
val index22 = array.lastIndexOf("马六")
println("index21=$index21 index22=$index22")
//index21=3 index22=-1
//（3）返回满足规则的第一个元素的角标，如果没有则返回-1
val index31 = array.indexOfFirst {
it.startsWith("张")
}
val index32 = array.indexOfFirst {
it.startsWith("马")
}
println("index31=$index31 index32=$index32")
//index31=0 index32=-1
//（4）返回满足规则的最后一个元素的角标，如果没有则返回-1
val index41 = array.indexOfLast {
it.startsWith("张")
}
val index42 = array.indexOfLast {
it.startsWith("马")
}
println("index41=$index41 index42=$index42")
//index41=3 index42=-1
}
4、枚举 enum
enum class Week {
Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, Sunday
}
fun todo(week: Week) {
when (week) {
in Week.Monday..Week.Friday -> println("上班")
else -> println("休息")
}
}
enum class Color(var r: Int, var g: Int, var b: Int) {
Red(255, 0, 0),
Green(0, 255, 0),
Blue(0, 0, 255)
}
fun main() {
println(Week.Monday) // Monday
// ordinal 枚举常数的序数(它在枚举声明中的位置，初始序数为0)
Week.values().forEach { println("${it.ordinal} -> $it") }
todo(Week.Wednesday) // 上班
todo(Week.Sunday) // 休息
println("${Color.Red}[${Color.Red.r}, ${Color.Red.g}, ${Color.Red.b}]")
// Red[255, 0, 0,]
}
5、数据类 data
/**
* 数据类：
* 1、使用关键字 data 定义数据类
* 2、会自动生成 构造函数、get、set、toString、hashCode、equals、copy、component
*/
data class News(var title: String, var desc: String, var image: String, var content: String)
fun main() {
val news = News("标题", "描述", "图片", "内容")
println(news.title) // 标题
println(news.desc) // 描述
println(news.image) // 图片
println(news.content) // 内容
println(news.toString()) // News(title=标题, desc=描述, image=图片, content=内容)
println(news.hashCode()) // 807819163
val newsCopy = news.copy()
println(newsCopy.toString()) // News(title=标题, desc=描述, image=图片, content=内容)
val newsCopyChange = news.copy("王者荣耀")
println(newsCopyChange.toString()) //News(title=王者荣耀, desc=描述, image=图片, content=内容)
println(news == newsCopy) // true
println(news === newsCopy) // false
println(news.component1()) // 标题 java: public final String component1() {return this.title;}
println(news.component2()) // 描述 java: public final String component1() {return this.desc;}
println(news.component3()) // 图片 java: public final String component1() {return this.image;}
println(news.component4()) // 内容 java: public final String component1() {return this.content;}
// 解构
val (title, desc, image, content) = news
println(title) // 标题
println(desc) // 描述
println(image) // 图片
println(content) // 内容
}
6、密封类 sealed
/**
* 密封类 sealed：封装的是类型
*/
sealed class NedStark {
class RobStark : NedStark()
class SansaStark : NedStark()
class AryaStark : NedStark()
class BrandonStark : NedStark()
}
class JonSnow : NedStark()
/**
* 判断有没有继承权
*/
fun hasRight(stark: NedStark): Boolean {
return when (stark) {
is NedStark.RobStark -> true
is NedStark.SansaStark -> true
is NedStark.AryaStark -> true
is NedStark.BrandonStark -> true
else -> false
}
}
fun main() {
val stark1 = NedStark.RobStark()
println(hasRight(stark1)) // true
val stark2 = JonSnow()
println(hasRight(stark2)) // false
}
7、List 集合
fun main() {
// 1、不可变 list
val list = listOf("毛晓彤", "林青霞", "赵露思", "毛晓彤", "毛晓彤")
println(list) // [毛晓彤, 林青霞, 赵露思, 毛晓彤, 毛晓彤]
println(list[0]) // 毛晓彤
println(list.indexOf("毛晓彤")) // 0
println(list.lastIndexOf("毛晓彤")) // 4
println(list.first()) // 毛晓彤
println(list.last()) // 毛晓彤
println(list.contains("赵露思")) // true
println(list.subList(1, 3)) // [林青霞, 赵露思]
println(list.size) // 5
println(list.lastIndex) // 4
println(list.asReversed()) // [毛晓彤, 毛晓彤, 赵露思, 林青霞, 毛晓彤]
val list2 = List(4) { index -> index * 2 }
println(list2) // [0, 2, 4, 6]
println(list2.binarySearch(4)) // 2
// 2、可变 list
val mutableList = mutableListOf("林青霞", "赵露思", "毛晓彤")
println(mutableList) //[林青霞, 赵露思, 毛晓彤]
mutableList.add("金晨")
println(mutableList) //[林青霞, 赵露思, 毛晓彤, 金晨]
mutableList.forEach { println(it) }
val mutableList2 = MutableList<Int>(3) { index -> index * index }
println(mutableList2) //[0, 1, 4]
// 3、java 中的 list
val arrList = ArrayList<String>()
val arrList1 = arrayListOf<String>()
val linkList = LinkedList<String>()
}
8、Set 集合
fun main() {
// 1.不可变 set
val set = setOf("A", "B", "A")
println(set) // [A, B]
// 2.可变 set
val mutableSet = mutableSetOf("A", "B", "A")
println(mutableSet) // [A, B]
mutableSet.add("C")
println(mutableSet) // [A, B, C]
val hashSet = hashSetOf("A", "B", "A")
println(hashSet) //[A, B]
hashSet.add("C")
println(hashSet) //[A, B, C]
val linkSet = linkedSetOf("A", "B", "A")
println(linkSet) //[A, B]
linkSet.add("C")
println(linkSet) //[A, B, C]
// 3.相关接口
println(set.size)
set.forEach {
println(it)
}
set.contains("A")
println(set.isEmpty())
println(set.indexOf("B"))
println(set.last())
println(set.first())
println(set.reversed())
//4.java 中的 set 集合
val s1 = HashSet<String>()
val s2 = LinkedHashSet<String>()
val s3 = TreeSet<String>()
}
9、Map 集合
fun main() {
// 1.不可变 Map
val map = mapOf("A" to 1, "B" to 2, "C" to 3)
println(map) // {A=1, B=2, C=3}
// 2.可变 Map
val mutableMap = mutableMapOf("A" to 1, "B" to 2, "C" to 3)
println(mutableMap) // {A=1, B=2, C=3}
mutableMap.put("D", 4)
println(mutableMap) // {A=1, B=2, C=3, D=4}
val hashMap = hashMapOf("A" to 1, "B" to 2, "C" to 3)
println(hashMap) // {A=1, B=2, C=3}
mutableMap.put("D", 4)
println(mutableMap) // {A=1, B=2, C=3, D=4}
val linkedMap = linkedMapOf("A" to 1, "B" to 2, "C" to 3)
println(linkedMap) // {A=1, B=2, C=3}
mutableMap["D"] = 4
println(mutableMap) // {A=1, B=2, C=3, D=4}
mutableMap["A"] = 5
println(mutableMap) // {A=5, B=2, C=3, D=4}
// 3.相关接口
mutableMap["B"] = 11
println(mutableMap) // {A=5, B=11, C=3, D=4}
println(mutableMap["B"]) // 11
println(mutableMap.keys) // [A, B, C, D]
println(mutableMap.values) // [5, 11, 3, 4]
for ((key, value) in mutableMap) {
println("{$key = $value}")
}
mutableMap.forEach { t, u ->
println("{$t = $u}")
}
// 4.java 中的 Map
val m1 = HashMap<String, Int>()
val m2 = LinkedHashMap<String, Int>()
val m3 = TreeMap<String, Int>()
}
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