). This operator converts any value to the non-null corresponding type. For example, a variable of type String? becomes of a value of type String. If the value to be converted is null then the operator throws an exception. 代码语言:javascript 代码运行次数:0 运行 AI代码解释 // it ...
val capitols = listOf("England" to "London", "Poland" to "Warsaw") capitols.forEach { (country, city) -> println("Capitol of $country is $city") } 请注意,Kotlin 通过提供一组接口和辅助方法(List与MutableList,Set与Set与MutableSet,Map与MutableMap等)区分可变和不可变集合: val list = lis...
println(filterIndexedToList) // [2, 4, 6, 8] //如果想在集合中找到指定类型的实例元素可以使用filterIsInstance。 val mixedList = listOf(1, 2, 3, "one", "two", 4, "three", "four", 5, 6, "five", 7) val strList = mixedList.filterIsInstance<String>() val intList = mixedList....
First, we’ll create a mutable list and add an element to it: val mutableList = mutableListOf<String>() mutableList.add("Hello") // Prints "Hello" println(mutableList.joinToString()) We can create an immutable list from our mutable list: val immutableList: List<String> = mutableList.to...
But if you want to create a list that could be mutable, Kotlin provides MutableList<T> class to define a mutable list. In this tutorial, we shall learn with examples on how to access and modify items in a list, and how to convert it to other Collection types. ...
The toList method returns an immutable ArrayList object. In case we need a mutable ArrayList, we can call the toMutableList method: inputSet.toMutableList(). 5. Conclusion In this article, we’ve learned how to convert between Set and List in Kotlin. As always, the code for these examples...
forecast.temp.min.toInt())} private fun convertDate(date: Long): String { val df = DateFormat.getDateInstance(DateFormat.MEDIUM, Locale.getDefault()) return df.format(date * 1000) } data class ForecastList(val city: String, val country: String,val dailyForecast:List<Forecast>) ...
Convert thelistback to amap. Below is the complete program: funmain(){valgivenMap=hashMapOf<String,Int>()givenMap["one"]=1givenMap["two"]=2givenMap["three"]=3givenMap["four"]=4givenMap["five"]=5givenMap["six"]=6println("Given map :")givenMap.forEach{(k,v)->println("$k=>...
KT-65441 K1: Remove JDK 21 getFirst()/getLast() in (Mutable)List interfaces KT-54792 Store program order of properties inside @kotlin.Metadata KT-59832 K2: Fix the TODO about merging values for labels in UnusedCheckerCompose compilerNew...
fun convertListToString(){ val nameCollection = listOf( "刘一", "陈二", "张三", "李四", "王五", "赵六", "孙七", "周八", "吴九", "郑十" ) val message = nameCollection.joinToString( separator = " ", prefix = "在古代,根据人口数量和宗族的影响力,有", ...