Kotlin数组容器

Arrays

Kotlin 标准库提供了arrayOf()创建数组,所以一般后缀是arrayOf()的，都可以找到相应的数组类型，以下是常用的几种,还有很多可以看看官方API

//普通数组val array = arrayOf(1, 2, 3)//字符串数组val strings = arrayOf("cn", "fr", "it")//int数组val numbers = intArrayOf(10, 20, 30)//运算数组val operationArray = Array(10, { k -> k * k })//空数组val longArray = emptyArray<Long>()//bean数组val studentArray = Array<MyBean>(2)studentArray[0] = MyBean("xiaoming")

List

List是有序容器，通过listOf创建，不过创建出来好像是只读序列，读写数组需要用MutableList显式修饰

fun list() {    var list = listOf<String>()    var notNull = listOfNotNull("1", "2", "3")    var nonNulls: List<String> = listOfNotNull<String>(null, "a", "b", "c")    var intList: List<Int> = listOf(1, 2, 3)    var emptyList: List<String> = emptyList<String>()    var doubleList: ArrayList<Double> = arrayListOf(84.88, 100.25, 999.99)    (nonNulls as java.util.ArrayList).addAll(arrayOf("x", "y"))    /**     * 读写数组需要用MutableList<T>显式修饰     */    var stringList:MutableList<String> = ArrayList()    stringList.add("zhangsan")    stringList.add("lisi")    var beanList: MutableList<MyBean> = ArrayList()    var myBean = MyBean()    myBean.name = "zhangsan"    myBean.age = 27    beanList.add(myBean)}

Map

几种常用的map

fun map() {    var map = mapOf("a" to 1, "b" to 2, "c" to 3)    var value = map["b"]    var states: MutableMap<String, String> =            mutableMapOf(                    "AL" to "Alabama",                    "AK" to "Alaska",                    "AZ" to "Arizona")    val myBean: java.util.HashMap<Int, MyBean> = hashMapOf(            1 to MyBean("ZhangSan", 12, false),            2 to MyBean("LiSi", 13, true))    val linkedHashMap: java.util.LinkedHashMap<String, String> =            linkedMapOf("red" to "#FF0000", "black" to "#000000", "white" to "#FFFFFF")    val sortedMap: java.util.SortedMap<Int, String> = sortedMapOf(4 to "d",            1 to "a", 3 to "c", 2 to "b")}

Set

Set是没有重复项的容器，可以用来去重

fun set(){    //int    val intSet: Set<Int> = setOf(1, 21, 21, 2, 6, 3, 2) //1,21,2,6,3    //hash    val hashSet: java.util.HashSet<MyBean> = hashSetOf(            MyBean("Zhang San",14, false),            MyBean("Zhang San",14, false))    //sort    val sortedIntegers: java.util.TreeSet<Int> = sortedSetOf(11, 0, 9, 11, 9, 8)}