kotlin中集合
fun main(arg: Array<String>) { //可读写的集合创建 val mutableListOf1 = mutableListOf<Int>(1, 2, 3) val mutableListOf2 = mutableListOf<Int>() val mutableSetOf1 = mutableSetOf<Int>(11, 22, 33) val mutableSetOf2 = mutableSetOf<Int>() val mutableMapOf1 = mutableMapOf<Int, String>(Pair(1, "name1"), Pair(2, "name2")) val mutableMapOf2 = mutableMapOf<Int, String>() //可读不可写的集合创建 val listOf1 = listOf<Int>(1, 2, 3) val of1 = setOf<Int>(1, 2, 3) val mapOf1: Map<Int, String> = mapOf<Int, String>(Pair(11, "name11"), Pair(22, "name22")) //list集合遍历 println(" ---------------------------------mutableListOf -------------------------------------") mutableListOf2.add(100)//添加数据 mutableListOf2.removeAt(0)//删除数据 for (i in mutableListOf1) { if (i==1){ } println(i) } println(" ------------------------------------listOf-----------------------------------------") val get = listOf1.get(0) println("索引0的值为"+get) for (i in listOf1) { println(i) } println(" ---------------------------------------mutableSetOf---------------------------------") mutableSetOf2.add(100)//添加数据 mutableSetOf2.remove(11)//删除数据 //set集合遍历 for (i in mutableSetOf1) { println(i) } println(" -------------------------------------SetOf-----------------------------------") for (i in of1) { println(i) } println(" ------------------------------mutableMapOf------------------------------------------") //map 集合遍历 for (entry in mutableMapOf1) { println(entry) } println(" --------------------------------mutableMapOf----------------------------------------") mutableMapOf2.put(3,"new name") mutableMapOf2.remove(2) for ((key, value) in mutableMapOf1) { println("key = $key value = $value") } println(" ------------------------------mapOf-------------------------------------------------") for (entry in mapOf1) { println(entry) } println(" --------------------------------mapOf-----------------------------------------------") for ((key, value) in mapOf1) { println("key = $key value = $value") } }
val toList = mutableListOf1.toList()//将可读写集合转为只读集合
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